Superconducting Properties Unit, National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
J Am Chem Soc. 2013 Nov 6;135(44):16507-16. doi: 10.1021/ja4074408. Epub 2013 Oct 22.
In continuation of the series of perovskite oxides that includes 3d(4) cubic BaFeO3 and 4d(4) cubic BaRuO3, 5d(4) cubic BaOsO3 was synthesized by a solid-state reaction at a pressure of 17 GPa, and its crystal structure was investigated by synchrotron powder X-ray diffraction measurements. In addition, its magnetic susceptibility, electrical resistivity, and specific heat were measured over temperatures ranging from 2 to 400 K. The results establish a series of d(4) cubic perovskite oxides, which can help in the mapping of the itinerant ferromagnetism that is free from any complication from local lattice distortions for transitions from the 3d orbital to the 5d orbital. Such a perovskite series has never been synthesized at any d configuration to date. Although cubic BaOsO3 did not exhibit long-range ferromagnetic order unlike cubic BaFeO3 and BaRuO3, enhanced feature of paramagnetism was detected with weak temperature dependence. Orthorhombic CaOsO3 and SrOsO3 show similar magnetic behaviors. CaOsO3 is not as conducting as SrOsO3 and BaOsO3, presumably due to impact of tilting of octahedra on the width of the t2g band. These results elucidate the evolution of the magnetism of perovskite oxides not only in the 5d system but also in group 8 of the periodic table.
在包括 3d(4)立方 BaFeO3 和 4d(4)立方 BaRuO3 的钙钛矿氧化物系列的延续中，5d(4)立方 BaOsO3 通过在 17 GPa 的压力下的固态反应合成，并通过同步加速器粉末 X 射线衍射测量研究了其晶体结构。此外，还测量了其在 2 至 400 K 温度范围内的磁化率、电阻率和比热。结果建立了一系列 d(4)立方钙钛矿氧化物，这有助于描绘不受从 3d 轨道到 5d 轨道的转变中局部晶格畸变影响的巡游铁磁性。迄今为止，还没有在任何 d 构型下合成过这样的钙钛矿系列。尽管立方 BaOsO3 不像立方 BaFeO3 和 BaRuO3 那样表现出长程铁磁有序，但在弱温度依赖性下检测到了增强的顺磁特征。正交的 CaOsO3 和 SrOsO3 表现出相似的磁行为。CaOsO3 的导电性不如 SrOsO3 和 BaOsO3，这可能是由于八面体倾斜对 t2g 带宽度的影响。这些结果阐明了钙钛矿氧化物的磁性不仅在 5d 体系中，而且在元素周期表的第 8 族中也在不断演变。
