Institute for Chemical Research, Kyoto University , Uji, Kyoto 611-0011, Japan.
Inorg Chem. 2013 Sep 16;52(18):10610-4. doi: 10.1021/ic401633c. Epub 2013 Aug 26.
Solid solutions of Pauli-paramagnetic CaCu3V4O12 and antiferromagnetic CaMn3V4O12 were prepared by a high-pressure synthesis technique. All samples crystallized in the A-site-ordered perovskite structure with isovalent Cu(2+) and Mn(2+) ions at the square-planar A' site. The V ion at the B site kept a charge state close to +4 in all of the solid solutions, and the electrons of V were delocalized and contributed to the metallic properties. The substitution of Mn(2+) for Cu(2+) in CaCu3V4O12, where both Cu and V electrons were delocalized, produced the S = 5/2 localized moments, and the spins at the Mn site interacted antiferromagnetically. Spin-glass-like magnetic behaviors due to the random distribution of Cu/Mn ions at the A' site were observed at intermediate compositions of the solid solution, whereas the antiferromagnetic transition was observed at the end composition CaMn3V4O12.
钙铜钒氧化物和钙锰钒氧化物的钙空位有序钙钛矿结构的 Pauli 顺磁固溶体和反铁磁固溶体通过高压合成技术制备而成。所有样品均结晶为 A 位有序钙钛矿结构，其中 Cu(2+)和 Mn(2+)离子占据四面体形 A'位。B 位 V 离子在所有固溶体中保持接近于+4 的电荷状态，V 离子的电子离域并贡献于金属性质。在 CaCu3V4O12 中，Mn(2+)取代 Cu(2+)，其中 Cu 和 V 电子均离域，产生 S = 5/2 局域磁矩，Mn 位的自旋呈反铁磁相互作用。在固溶体的中间组成部分，由于 A'位的 Cu/Mn 离子的随机分布，观察到类似 spin-glass 的磁行为，而在固溶体的末端组成 CaMn3V4O12 中，观察到反铁磁转变。
