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Chemische Transportreaktionen weisen ein gemeinsames Merkmal auf: In Gegenwart eines gasförmigen Reaktionspartners, des Transportmittels, wird eine feste oder flüssige Komponente verflüchtigt. An anderer Stelle scheidet sie sich meist in Form gut ausgebildeter Kristalle wieder ab. So ist der Chemische Transport z. B. für den Festkörperchemiker ein unentbehrliches Verfahren zur Herstellung reiner, gut kristallisierter Feststoffe. Als umfassendes Handbuch behandelt dieses Werk die vielseitigen Aspekte von chemischen Transportreaktionen: Von der Grundlagenforschung bis hin zur praktischen Bedeutung, beispielsweise für die Funktionsweise von Halogenlampen.
Since their first recognition in mineral forming processes
some 150 years ago chemical vapor transport reactions (CVTR) have attracted continuous scientific interest. Due to the pioneering work of Harald Schäfer quantitative understanding and exploitation of transport reactions for crystal growth, synthesis, investigation of high-temperature gas species, and thermodynamic studies have become possible. Renewed interest in CVT is triggered by the demand of material sciences for novel compounds with tailor-made physical properties and by the need for efficient recycling strategies for various metals from industrial waste.
Chemical Vapour Transport of Bismuth and Antimony Chalcogenides M2Q3 (M = Sb, Bi, Q = Se, Te)
(2010)
Thermodynamic modelling of the ternary systems M/Q/I (M = Sb, Bi, Q = Se, Te) indicated solid-gas equilibria suitable for chemical vapour transport of bismuth and antimony chalcogenides. The predictions of the modelling were confirmed by transport experiments on a transport balance. The optimum transport conditions using iodine as transport agent were determined for all systems to: ϑsource = 500 °C and ϑsink = 450 °C. For ΔT > 50 K the sequential transport of chalcogenide iodides MQI followed by M2Q3 occurs. Thermodynamic standard data of the gas species SbI(g) were concluded from equilibrium calculations: ΔH0f,298(SbI(g)) = 106 ± 3 kJ·mol–1; S0298(SbI(g)) = 255 ± 3 J·mol–1·K–1; Cp(SbI(g)) = 37 ± 1 J·mol–1·K–1
The term chemical vapor transport (CVT) summarizes a variety of reactions that show one common feature: a condensed phase, typically a metallic or salt like solid, is volatilized in the presence of a gaseous reactant, the so-called transport agent, and deposits elsewhere, usually in the form of crystals. The deposition will take place if the site of volatilization and the site of crystallization have different temperatures. In many cases, chemical vapor transport is associated with a purification effect. CVT-reactions of elements, oxides, sulfides, selenides, tellurides, phosphates, sulfates, halides, oxide halides, phosphides, arsenides, intermetallics, and so on, are known.
A variety of processes of crystal growth proceeds via the gas phase. If the initial solid material is volatilized in a heterogeneous reaction under presence of a gaseous reactant, the transport agent, the term Chemical Vapor Transport Reaction (CVT) is applied. Crystallization processes by CVT are known for both elements, intermetallics, binary and complex oxides, halides, chalcogenides, and pnictides. Even if the formation of volatile halides is a common feature of almost all vapor transport reactions, significant differences are there concerning the choice of a suitable transport agent depending on the nature of the initial solid phase. Actually, the appropriateness of transport agents for the respective transport reaction can be described in a thermodynamic way. Besides some basic principles for systematic evaluation more practical recommendations for suitable experimental conditions are given for CVT of different classes of inorganic materials.
Chemische Transportreaktionen weisen ein gemeinsames Merkmal auf: In Gegenwart eines gasförmigen Reaktionspartners, des Transportmittels, wird eine feste oder flüssige Komponente verflüchtigt. An anderer Stelle scheidet sie sich meist in Form gut ausgebildeter Kristalle wieder ab. So ist der Chemische Transport z. B. für den Festkörperchemiker ein unentbehrliches Verfahren zur Herstellung reiner, gut kristallisierter Feststoffe.
Als umfassendes Handbuch behandelt dieses Werk die vielseitigen Aspekte von Chemischen Transportreaktionen: Von der Grundlagenforschung bis hin zur praktischen Bedeutung, beispielsweise für die Funktionsweise von Halogenlampen.
This comprehensive handbook covers the diverse aspects of chemical vapor transport reactions from basic research to important practical applications. The book begins with an overview of models for chemical vapor transport reactions and then proceeds to treat the specific chemical transport reactions for the elements, halides, oxides, sulfides, selenides, tellurides, pnictides, among others. Aspects of transport from intermetallic phases, the stability of gas particles, thermodynamic data, modeling software and laboratory techniques are also covered. Selected experiments using chemical vapor transport reactions round out the work, making this book a useful reference for researchers and instructors in solid state and inorganic chemistry.
This comprehensive handbook covers the diverse aspects of chemical vapor transport reactions from basic research to important practical applications. The book begins with an overview of models for chemical vapor transport reactions and then proceeds to treat the specific chemical transport reactions for the elements, halides, oxides, sulfides, selenides, tellurides, pnictides, among others. Aspects of transport from intermetallic phases, the stability of gas particles, thermodynamic data, modeling software and laboratory techniques are also covered. Selected experiments using chemical vapor transport reactions round out the work, making this book a useful reference for researchers and instructors in solid state and inorganic chemistry.
Adaptation Planning Framework to Climate Change for the Urban Area of Ho Chi Minh City, Vietnam
(2009)
Situated in an intra-tropical and low elevation coastal zone, the developing megacity of Ho Chi Minh City is vulnerable to many of the adverse impacts of the present and future changes in climate. In consideration of climate change and urban development interrelations, the research case for adapting to climate change and the risks and opportunities of adaptation are set out. Based on the in-depth assessment of the vulnerability of Ho Chi Minh City, the categorized urban environment in form of a spatially explicit information system will act as a matrix for the formulation of appropriate adaptation strategies for future development and redevelopmentpolicies. The resulting Adaptation Planning Framework should form the future basis for spatially-explicit decision-making processes related to sustainable urban planning and development in HCMC.
Development of salt hydrate eutectics as latent heat storage for air conditioning and cooling
(2014)
Sustainable air conditioning systems require heat reservoirs that operate between 4 and 20 ◦C. A systematic search for binary and ternary eutectics of inorganic salts and salt hydrates with melting temperatures in this temperature regime and with high enthalpies of fusion has been performed by means of differential scanning calorimetry (DSC). Promising results were obtained for the pseudo-ternary system Zn(NO3)2·6H2O, Mn(NO3)2·4H2O, and KNO3 with the melting temperature range 18–21 ◦C and the enthalpy of fusion of about 110 kJ kg−1. Suitable nucleating and thickening agents have been found and tested to prevent the mixture from supercooling and phase separation.
This paper presents an investigation of primary breakup of planar turbulent liquid jets and breakup properties at the surface of turbulent jets in still air at standard conditions. Numerical simulations are carried out for jet exit Reynolds number 23000 and Weber numbers in the range [102–107].
Due to the limitation of direct numerical simulation (DNS) to moderate Reynolds numbers, a stochastic 1D ansatz based on the one-dimensional turbulence (ODT) model is used to simulate a planar liquid jet with a high lateral resolution. ODT permits an affordable high resolution of interface and single-phase property gradients which are key for understanding the local behavior. ODT is a stochastic model simulating turbulent flow evolution along a notional 1D line of sight by applying instantaneous maps to represent the effect of individual turbulent eddies on property profiles. The most relevant mechanisms that influence the primary breakup of liquid jets are found to be represented accurately based on comparisons to experiments and correlations reported in the literature. Building on this finding, future work will focus on the statistics of droplets generated by primary breakup, both to investigate their relationship to breakup mechanisms and to provide input to models of secondary breakup and subsequent spray evolution.
The paper presents the use of indicators in a site-specific assessment method for strategic environmental assessment in regional land use planning (here: SEA-REP). It is explained with the example of the state of environment indicator ‘LUCCA 4—Urban Areas at Risk of Flooding’, how SEA as a decision-aiding instrument can contribute to the prevention of conflicts with policy for adaptation to climate change.
The method begins with the determination of impact factors for SEA. In the presented study, the physical impact factors of land consumption, land use change, and directed flooding were recognised. A core problem during the selection of indicators for land uses for the adaptation to climate change (here: LUCCA) and the derivation of assessment thresholds was a lack of region-wide policy objectives for the protection of land and resources. Therefore, in a second step, regional environmental orientation objectives were derived from national and EU environmental policy. A standard method for the selection of LUCCA indicators and the derivation of assessment thresholds for conflict analysis is described. Three classes of conflict classification for regional plan designations on the individual site are proposed. It is recommended that future adaptation measures of regional land use planning should be designations of specific land uses as priority areas for urban areas prone to flood risk.
Im Rahmen der Strategischen Unweltpruefung (SUP) ist, soweit erforderlich, eine grenzueberschreitende Beteiligung durchzufuehren. Bei dieser sind unterschiedliche administrative, rechtliche, planerische und kulturelle Rahmenbedingungen der beteiligten Staaten zu beruecksichtigen. Sie bedarf daher einer gruendlichen Vorbereitung sowie der Entwicklung geeigneter Verfahren, fuer die bisher kaum auf Beispiele und Erfahrungen zurueckgegriffen werden kann. Vor diesem Hintergrund wurde im INTERREG-Ill-A-Projekt "transSEA" am Beispiel der grenzueberschreitenden Beteiligung in der Regionalplanung zwischen Sachsen, Polen und Tschechien ein Verfahrensvorschlag entwickelt, der in diesem Beitrag vorgestellt wird.
Landschaftsverbrauch, großräumige Versiegelungen und Bodenkontaminationen haben dazu geführt, daß das Umweltmedium Boden in den letzten Jahren eine zunehmende Bedeutung als Schutzgut erfahren hat. Bodenschutz bedeutet nicht nur, die Nutzungsfunktionen der Böden in ihrer Leistungsfähigkeit zu erhalten bzw. wiederherzustellen, sondern auch, die natürlichen Bodenfunktionen vorsorgend zu schützen. Dabei hat der präventive Bodenschutz vor allem eine standortgerechte Nutzung von Flächen zum Ziel. Vor allem für planerische Zwecke werden künftig verstärkt bodenbezogene Bewertungskriterien und -abläufe erforderlich, die die Fähigkeit von Boden zur Erfüllung verschiedener Funktionen im Naturhaushalt kennzeichnen. Die Funktionsfähigkeit eines Bodens laßt sich dabei beispielsweise recht gut mit Hilfe seiner natürlichen Bodenfunktionen Produktions-, Lebensraum- und Regelungsfunktion beschreiben und bewerten.
Main development steps of the modern European legislation in the field of environmental assessment
(2007)
Requirements and Issues with Implementing SEA as a Sustainable Development Instrument in Ukraine
(2011)
Comparative Analysis of Environmental and Social Impacts of Cocoa Production: Case Study Cameroon
(2014)
Criteria and Requirements for the Implementation of Sustainable Development Policy in Ukraine
(2005)
Implementation of sustainable development principles primarily involves stating appropriate criteria and requirements for reformation of the development management. The main groups of sustainable development indicators (social indicators, economic indicators, environmental indicators, institutional indicators, structural indicators) are formulated. In the view of objectives set for economic and social reforms in Ukraine, there is a need in further specification of these indicator groups, their legislative support with the purpose of organising monitoring of efficiency of state policies and programmes.
The administrative reforms conducted in Ukraine include transformation of regional administration. Aims, objectives and methods of Strategic Environmental Assessment (SEA) are accordant with conducted administrative reforms. At present all plans, programmes and policies developed in Ukraine, which can have significant impact on environment are subject to SEA. The main reasons, which determine necessity of implementing SEA into procedures of regional planning, are investigated in this paper.
В статье анализируется проблема регионального планирования в контексте современной концепции обеспечения устойчивого развития и учета факторов изменяющегося климата. Исследованы и предложены основные направления реформирования регионального планирования в Украине с точки зрения имплементации европейских методов экологизации стратегий развития регионов.
Artikel-Nr. L VI-3/10
(2001)
Cultural heritage still suffers from the lack of a specific and systematic risk assessment process despite emerging recent investigations on protection of such outstanding properties from natural hazards. Vulnerable attributes of heritage sites are conveying irreplaceable values that make it much more complicated to identify and analyse potential disaster losses to those elements. This paper aims to develop a methodology of disaster risk assessment specified to cultural heritage sites in an interdisciplinary framework. The existing methods and approaches of risk assessment as well as relevant global practices are applied to fulfil the aim.
The Need for Implementation of Adaptation Measures for Global Climate Change into Regional Planning
(2007)
Phase formation, stability, crystal and electronic structures of IrPTe are investigated from experiment and quantum chemical calculations. The phase formation is studied from thermodynamic data and CalPhaD modeling. Applying a high-temperature gas-balance a formation pathway for IrPTe is studied from the elements and the binary parent compounds IrTe2 and IrP2. The obtained paracostibite (CoSbS) type structure contains rarely occurring heteroatomic P-Te dumbbells. The stability of IrPTe and the found structure is studied from DFT calculations with respect to the elements, IrTe2 and IrP2, and possible polymorphs. Probable metastable modifications with XY dumbbells (as known for isoelectronic compounds like CoAsS) are obtained from systematic DFT modelling. Phase transitions are predicted form the equation of states (EOS). According to its electronic band structure IrPTe is predicted as small gap (Eg = 0.5 eV) semiconductor.
The reaction of antimony and selenium in the Lewis-acidic ionic liquid 1-butyl-3-methyl-imidazolium tetrachloridoaluminate, [BMIm]Cl·4.7AlCl3, yielded dark-red crystals of [Sb2Se2]AlCl4. The formation starts above 160 °C; at about 190 °C, irreversible decomposition takes place. The compound crystallizes in the triclinic space group Pequation image with a = 919.39(2) pm, b = 1137.92(3) pm, c = 1152.30(3) pm, α = 68.047(1)°, β = 78.115(1)°, γ = 72.530(1)°, and Z = 4. The structure is similar to that of [Sb2Te2]AlCl4 but has only half the number of crystallographically independent atoms. Polycationic chains 1∞[Sb2Se2]+ form a pseudo-hexagonal arrangement along [01-1], which is interlaced by tetrahedral AlCl4– groups. The catena-heteropolycation 1∞[Sb2Se2]+ is a sequence of three different four-membered [Sb2Se2] rings. The chemical bonding scheme, established from the topological analysis of the real-space bonding indicator ELI-D, includes significantly polar covalent bonding in four-member rings within the polycation. The rings are connected into an infinite chain by homonuclear non-polar Sb–Sb bonds and highly polar Sb–Se bonds. Half of the selenium atoms are three-bonded.
Cd4Cu7As, the first representative of a fully ordered, orthorhombically distorted MgCu2 Laves phase
(2012)
The ternary Laves phase Cd4Cu7As is the first intermetallic compound in the system Cu–Cd–As and a representative of a new substitution variant for Laves phases. It crystallizes orthorhombically in the space group Pnnm (No. 58) with lattice parameters a = 9.8833(7) Å; b = 7.1251(3) Å; c = 5.0895(4) Å. All sites are fully occupied within the standard deviations. The structure can be described as typical Laves phase, where Cu and As are forming vertex-linked tetrahedra and Cd adopts the structure motive of a distorted diamond network. Cd4Cu7As was prepared from stoichiometric mixtures of the elements in a solid state reaction at 1000 °C. Magnetic measurements are showing a Pauli paramagnetic behavior. During our systematical investigations within the ternary phase triangle Cd–Cu–As the cubic C15-type Laves phase Cd4Cu6.9(1)As1.1(1) was structurally characterized. It crystallizes cubic in the space group Fd3m̅ with lattice parameter a = 7.0779(8) Å. Typically for quasi-binary Laves phases Cu and As are both occupying the 16c site. Chemical bonding, charge transfer and atomic properties of Cd4Cu7As were analyzed by band structure, ELF, and AIM calculations. On the basis of the general formula for Laves phases AB2, Cd is slightly positively charged forming the A substructure, whereas Cu and As represent the negatively charged B substructure in both cases. The crystal structure distortion is thus related to local effects caused by Arsenic that exhibits a larger atomic volume (18 Å3 compared to 13 Å3 for Cu) and higher ionicity in bonding.
The potential of industrial porous concrete for using as a template for the synthesis of porous carbon materials has been investigated. Carbon replicas of porous concrete have been prepared by carbonization of sucrose. The pores of the resulting carbon materials range from the macropore to the micropore region, pointing to a hierarchy.
Several methods are established in thermal analysis to investigate phase formation, phase transition, and decomposition reactions. The analysis of phase equilibria with volatile components is particularly feasible by using standard method of thermogravimetry. Hardly any investigations of phase formation reactions are possible to realize if one of the components is lost by vaporization. By using the “High-Temperature Gas-Balance” (HTGB), the vapor phase is enclosed in a silica ampoule and thus forms an equilibrium gas phase in permanent contact with the solid phase. The measurement signal Δmmeas is caused by change of the leverage of the horizontal balance support during evaporation and condensation. The application of the HTGB allows the analysis of solid–gas equilibria in the working range from 0.01 till 15 bar at temperatures up to 1,100 °C. The first comparison of evaporation reactions determined by standard thermogravimetric analyses and by measurements using the HTGB is given for the inorganic systems: P, As, SeO2, PtI2, and Hg/I.
Back in black: All metastable and stable phases can be identified for the solid solution arsenic/phosphorus by a combination of quantum-chemical calculations and investigations of the phase formation. Reaction paths for phase formations and transitions in situ were also evaluated. The results show that orthorhombic black arsenic (o-As) is metastable in pure form and has only been previously obtained by stabilizing impurities.
The phosphide tellurides Zr2+δPTe2 (0 ≤ δ ≤ 1) can be synthesized from the elements in a solid state reaction or by thermal decomposition of Z. Zr2PTe2 decomposes under release of Te2(g) + P4(g) forming the homogeneity range Zr2+δPTe2. The growth of single crystals of Zr2+δPTe2 succeeded by chemical vapour transport using iodine as transport agent from 830 °C in direction of higher temperatures up to 900 °C. Zr2+δPTe2 crystallizes in the rhombohedral space group R-3m (no. 166) with lattice parameters a = 383(1)…386(1) pm and c = 2935(4)…2970(4) pm for δ = 0…1, respectively. Single crystal data have been determined for Zr2.40(2)PTe2 with lattice parameters a = 385.24(4) pm and c = 2967.8(4) pm.
The electronic structure and chemical bonding in Zr2+δPTe2 was investigated by the linear muffin–tin orbital (LMTO) method. Both Zr2PTe2 and Zr3PTe2 show non-vanishing DOS values at the Fermi level (EF) indicating metallic character. According to COHP bonding analyses, mainly the heteroatomic Zr–P and Zr–Te bonds are responsible for the structural stability of Zr3PTe2. The new Zr2–Te bond, which is not present in Zr2PTe2, is stronger than Zr1–Te and is thought to be responsible for the stability of phases having Zr in excess.
Despite cultural heritage has being affected by construction and infrastructure projects associated with urban development in historic cities worldwide, protection of such irreplaceable assets and their associated values has not been adequately addressed through a comprehensive methodology of impact assessment. This paper aims to review the existing methodologies, approaches, and tools regarding Heritage Impact Assessment (HIA) methodology, and to develop an impact assessment procedure in the context of new urban development. The methodology is applied to the case of Masjed-e Jame of Isfahan. The required data is collected through a fieldwork for identification and classification of impacts of Atiq project on the property. Subsequently, the collected data is analysed through impact assessment matrix, and eventually, appropriated mitigation strategies to reduce negative impacts on the property are determined. The proposed impact assessment methodology in the HIA procedure provides a systematic framework for identifying, assessing and mitigating potential impacts of new urban development on cultural heritage properties, which is supportive for urban planners, cultural decision makers, heritage conservators and experts toward developing more integrated approach to heritage protection in context of sustainable development.
The application of the EnPhaSyn (theoretical Energy diagrams, experimental Phase formation, Synthesis and characterisation) concept is reviewed with respect to prediction of structures and stability of element allotropes and compound polymorphs, their phase formation and transition processes, and their directed synthesis, respectively. Therein, the relative energetical stability (En) of target compounds and possible decomposition are determined from quantum chemical DFT calculations. Phase formation and transition (Pha) is probed by a gas balance method, developed as high temperature gas balance concept. It helped to study the synthesis and stability range of several compounds experimentally. Applications of the concept and synthesis principles (Syn) of non-equilibrium phases are presented for allotropes of P, As, P1-xAsx, as well as binary and ternary compounds including the Zintl and Laves like phases IrPTe, NiP2, CoSbS, NiBiSe, Li0.2CdP2, Cu3CdCuP10, and Cd4Cu7As.
Structural engineering of topological bulk materials is systematically explored with regard to the incorporation of the buckled bismuth layer [Bi₂], which is a 2D topological insulator per se, into the layered BiTeI host structure. The previously known bismuth telluride iodides, BiTeI and Bi₂TeI, offer physical properties relevant for spintronics. Herewith a new cousin, Bi₃TeI (sp.gr. R3m, a = 440.12(2) pm, c = 3223.1(2) pm), joins the ranks and expands this structural family. Bi₃TeI = [Bi₂][BiTeI] represents a stack with strictly alternating building blocks. Conditions for reproducible synthesis and crystal-growth of Bi₂TeI and Bi₃TeI are ascertained, thus yielding platelet-like crystals on the millimeter size scale and enabling direct measurements. The crystal structures of Bi₂TeI and Bi₃TeI are examined by X-ray diffraction and electron microscopy. DFT calculations predict metallic properties of Bi₃TeI and an unconventional surface state residing on various surface terminations. This state emerges as a result of complex hybridization of atomic states due to their strong intermixing. Our study does not support the existence of new stacking variants BiₓTeI with x > 3; instead, it indicates a possible homogeneity range of Bi₃TeI. The series BiTeI–Bi₂TeI–Bi₃TeI illustrates the influence of structural modifications on topological properties.
This article explores the concept of partnership as an applied tool for modernisation of university education and formulated specific characteristics of university partnership for the purpose of promoting sustainable development. The authors discussed the main types and functions of partnership in the context of transition of Ukrainian universities towards the new model of higher education. The article revealed the differences and interrelation between internal and external partnership for promoting principles of sustainable development in the higher education. Finally, the authors analysed the experience of partnership relations between the National Mining University and the Brandenburg University of Technology Cottbus-Senftenberg in improving the standard of knowledge and increasing awareness about various aspects of sustainable development.
Undoubtedly, Ho Chi Minh City is not just the biggest city in Vietnam, but also its economic centre. With its regional location as hub in Southeast Asia, its airport, harbour and the intersection of main roads, the metropolis is well connected within the domestic as well as the most important international markets. Located downstream of the Saigon-Dong Nai River with a relatively flat terrain, the city traditionally has a strong relationship to water. It is located at the north-eastern fringe of the Mekong Delta and its southern part is connected to the east sea. Major parts of the city are situated on low-lying marshy lands that are crossed by a complex network of canals and rivers. These topographic and geographic conditions make the city extremely sensitive to various flood sources.
The adaptation of mega-urban regions and their landscapes to climate change is predominantly a spatial planning matter. Rapidly developing Asian megacities, like Ho Chi Minh City (HCMC) in Vietnam, need to become more resilient and less vulnerable to climate change. Our contribution takes spatial planning as the starting point. It highlights opportunities and challenges for spatially-explicit adaptation strategies in HCMC and shows how adaptation to climate change can be used to influence land-use planning and future urban development. Special attention is given to urban water management issues. Here the focus lies on risk management and non-structural protection measures to lessen climate-related urban risks. For rapidly developing mega-urban regions the need for focused support and guidance in formulating and embedding suitable adaptation policies and spatially explicit zoning regulations is apparent. Within its multi-stakeholder environment borne out of conflicting interests, land use planning requires more than ever science-based information to formulate spatially explicit and integrated urban climate adaptation policies.
Based on the experience of thermo-chemical studies on a High-Temperature Gas-Balance a time dependent analysis has been developed for the investigations of the kinetics of solid-gas reactions. The course of solid-gas reactions can be examined unambiguously by separation of the initial solids. By this setup the visualization of different stages of solid-gas reaction (vaporization, phase formation) becomes feasible. Time dependent analysis of the formation of FeAs results in an assignment of the underlying principles of kinetics derived from the conversion factor α.
Inorganic solid-state synthesis with phosphorus and tellurium requires a careful control of the reaction parameters because of the high volatility of the components. This initial disadvantage can be used as a benefit for the investigation of phase formation mechanisms by analyzing the individual vapor pressure behavior. The high-temperature gas-balance is introduced as a device for detection of heterogeneous solid-gas equilibria in closed reaction systems. The experimentally challenging synthesis of the phosphide telluride Zr₂PTe₂ is examined as a model system: optimized synthesis runs at lower temperatures (ϑ = 650 °C) in a faster time, while the quantity as well as the crystalline powder quality is increased. A stepwise solid-solid reaction of zirconium and tellurium according to Ostwald's rule of stages and the shrinking core model is revealed while phosphorus sublimes and subsequently condenses to react to the ternary compound. Additional phenomena such as melting, expansion, and mechanical instabilities can be observed that broaden the possibilities of the gas- balance.