Details

Autor(en) / Beteiligte

• Pet'kov, V I
• Orlova, A I

Titel

Crystal-Chemical Approach to Predicting the Thermal Expansion of Compounds in the NZP Family

Ist Teil von

• Inorganic materials, 2003-10, Vol.39 (10), p.1013-1023

Erscheinungsjahr

2003

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The interest in framework phosphates is motivated by their near-zero thermal expansion, a unique feature which makes them potentially attractive for the production of high-performance ceramics. Owing to this feature, and also to the high melting point, good chemical stability and radiation resistance, great hardness, high mechanical strength, and low thermal conductivity, such phosphates are suitable for use in articles requiring high thermal-shock resistance (refractory lining and its elements, fixtures for close-tolerance brazing, semiconductor substrates, catalyst supports, and optical benches), in electronics (ceramic electrolytes and substrates), in 'mechanical engineering and transportation systems (parts of motors), and in power engineering (radiation-resistant insulating materials and nuclear waste disposal materials). The information accumulated to date provides no consistent picture of the correlation between the structure of the {[L2(PO4)3]p-}3(infinity) framework compounds, their physical and chemical properties, and their engineering performance. Abstract-The general structural aspects of phosphates with {[L2(PO4)3]p-}3(infinity) frameworks (L = octahedral cation) are considered, and the possible isomorphous substitutions in NaZr2(PO4)3 (NZP) phosphates are analyzed. The available data on the thermal expansion of NZP materials in the range 293-1273 K, together with crystal-chemical data on their structure, are used to identify the processes underlying the thermal expansion of these materials. The results provide basic guidelines in designing NZP-based materials with controlled (ultralow) thermal expansion and near-zero expansion anisotropy.