High-pressure synthesis and physical properties of A-site ordered perovskites
ABO3-type perovskite oxides exhibit a wide variety of interesting physical properties such as superconductivity, colossal magnetoresistance, multiferroic behavior etc. For a simple ABO3 perovskite, if three quarters of the A site is replaced by a transition metal A', then the so-called A-site ordered double perovskite with the chemical formula of AA'3B4O12 can form. Since both A' and B sites accommodate transition metal ions, in addition to conventional B-B interaction, the new A'-A' and/or A'-B interaction is possible to show up, giving rise to the presence of many novel physical properties. Here we will show our recent research work on the high-pressure synthesis of several A-site ordered perovskites as well as a series of interesting physical properties like temperature- and pressure-induced intermetallic charge transfer, negative thermal expansion, magnetoelectric coupling multiferroic and so on. [1-3]
