Injac Sean, Yuen Alexander K L, Avdeev Maxim, Wang Chun-Hai, Turner Peter, Brand Helen E A, Kennedy Brendan J
School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia.
Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, ANSTO, Lucas Heights, New South Wales 2234, Australia.
Inorg Chem. 2020 Mar 2;59(5):2791-2802. doi: 10.1021/acs.inorgchem.9b03118. Epub 2020 Feb 14.
Oxides of the form O with = K, Rb, Cs and = Ru and Os have been synthesized and characterized by diffraction and magnetic techniques. For = K the oxides adopted the tetragonal (4/) scheelite structure. RbOsO, which crystallizes as a scheelite at room temperature, underwent a continuous phase transition to 4/ near 550 K. RbRuO and CsOsO were found to crystallize in the orthorhombic () pseudoscheelite structure, and both displayed discontinuous phase transitions to 4/ at high temperatures. CsOsO was determined to undergo a phase transition to a 2/ structure below 140 K. CsRuO crystallizes with a baryte-type structure at room temperature. Upon heating CsRuO a first order phase transition to the scheelite structure in 4/ is observed at 400 K. A continuous phase transition is observed to 222 below 140 K. DC magnetic susceptibility data is consistent with long-range antiferromagnetic ordering at low temperatures for all compounds except for CsOsO, which is paramagnetic to 2 K. The effective magnetic moments are in agreement with the spin only values for an = 1/2 quantum magnet. Effective magnetic moments calculated for Os compounds were lower than their Ru counterparts, reflective of an enhanced spin orbit coupling effect. A magnetic structure is proposed for RbRuO consisting of predominately antiferromagnetic (AFM) ordering along the 001 direction, with canting of spins in the 100 plane. A small ordered magnetic moment of 0.77 μ was determined.
已合成了通式为O（其中 = K、Rb、Cs且 = Ru和Os）的氧化物，并通过衍射和磁性技术对其进行了表征。对于 = K，这些氧化物采用四方晶系（4/）白钨矿结构。室温下以白钨矿形式结晶的RbOsO在550 K附近经历了向4/的连续相变。发现RbRuO和CsOsO以正交晶系（）假白钨矿结构结晶，并且两者在高温下均表现出向4/的不连续相变。确定CsOsO在140 K以下会发生向2/结构的相变。CsRuO在室温下以重晶石型结构结晶。加热CsRuO时，在400 K观察到向4/白钨矿结构的一级相变。在140 K以下观察到向222的连续相变。直流磁化率数据表明，除了CsOsO在2 K时为顺磁性外，所有化合物在低温下均存在长程反铁磁有序。有效磁矩与 = 1/2量子磁体的仅自旋值一致。计算得出的Os化合物的有效磁矩低于其Ru对应物，这反映了自旋轨道耦合效应增强。提出了一种RbRuO的磁结构，其主要沿001方向存在反铁磁（AFM）有序，自旋在100平面内倾斜。确定了一个小的有序磁矩为0.77 μ。
