Ca Double Double and Double Triple Perovskites

Complex Ferrimagnetism and Magnetoresistance Switching in Ca-based Double Double and Triple Double Perovskites. We have used high pressures and temperatures to synthesize the cation ordered AA′BB′O6 perovskites CaMnFeReO6, CaMnMnReO6, and Ca(Mn0.5Cu0.5)FeReO6. Neutron diffraction reveals complex ferrimagnetic orders in all three materials; CaMnFeReO6 and Ca(Mn0.5Cu0.5)FeReO6 have large room temperature magnetizations with low temperature switching of magnetoresistance in the latter material, and CaMnMnReO6 displays a high coercivity of 1.3 T at low temperatures.

基于钙的双双型与三三型钙钛矿（Perovskites）中的复杂亚铁磁性与磁阻开关特性。本研究采用高压高温手段合成了阳离子有序的AA'BB'O6型钙钛矿材料：CaMnFeReO6、CaMnMnReO6及Ca(Mn₀.₅Cu₀.₅)FeReO6。中子衍射（Neutron diffraction）表征结果显示，三种材料均呈现复杂的亚铁磁有序结构；其中CaMnFeReO6与Ca(Mn₀.₅Cu₀.₅)FeReO6均具备较高的室温磁化强度，且后者在低温下表现出磁阻开关效应；而CaMnMnReO6在低温下展现出1.3特斯拉的高矫顽力（coercivity）。