Search and chemical modification of potential negative thermal expansion compounds

负热膨胀(NTE)化合物随着温度的升高表现出体积收缩，对纳米技术的应用具有重要意义。然后，预计会有一种新的NTE化合物。为了寻找和开发新的NTE化合物，本研究探索了一种潜在的NTE化合物的化学修饰方法，使其具有潜在的特征。对潜在的NTE化合物--ZrV2O7和HfV2O7的量热研究表明，NTE和潜在的NTE化合物之间存在结构差异。Al_2B_3O_(12)体系中的固溶体表现出取代对NTE性质的影响。通过对著名的NTE化合物--ZrW2O8和Sc掺杂的ZrW2O8的电子显微镜观察，说明了晶格缺陷对NTE性能稳定性的重要性。

Negative thermal expansion (NTE) compounds, which show volumetric contraction with increasing temperature, are important for application to nanotechnology. Then, a new NTE compound has been expected. In order to a guideline to search and develop the new NTE compounds, a method of chemical modification of potential NTE compounds to emerge the potential feature was investigated in the present study. The calorimetric investigation on ZrV2O7 and HfV2O7, which are the potential NTE compounds, indicated a structural difference between the NTE and the potential NTE compounds. The solid solution in A2B3O12 system exhibited the effects of substitution on the NTE feature. The electron microscopic observation of ZrW2O8, which is a famous NTE compound, and Sc-doped ZrW2O8 showed the importance of defects in lattice for the stability of the NTE property.