Nikulin A Yu, Zvereva E A, Nalbandyan V B, Shukaev I L, Kurbakov A I, Kuchugura M D, Raganyan G V, Popov Yu V, Ivanchenko V D, Vasiliev A N
Chemistry Faculty, Southern Federal University, 7, ul. Zorge, 344090 Rostov-on-Don, Russia.
Faculty of Physics, Moscow State University, 119991 Moscow, Russia.
Dalton Trans. 2017 May 9;46(18):6059-6068. doi: 10.1039/c6dt04859e.
MSbO compounds (M = Mg, Co, Ni, Cu, Zn) are known in the tetragonal trirutile forms, slightly distorted monoclinically with M = Cu due to the Jahn-Teller effect. In this study, using a low-temperature exchange reaction between ilmenite-type NaSbO and molten MSO-KCl (or MgCl-KCl) mixtures, these five compositions were prepared for the first time as trigonal layered rosiaite (PbSbO)-type phases. Upon heating, they irreversibly transform to the known phases via amorphous intermediates, in contrast to previously studied isostructural MnSbO, where the stable phase is structurally related to the metastable phase. The same method was found to be applicable for preparing stable rosiaite-type CdSbO. The formula volumes of the new phases show an excellent correlation with the ionic radii (except for M = Cu, for which a Jahn-Teller distortion is suspected) and are 2-3% larger than those for the known forms although all coordination numbers are the same. The crystal structure of CoSbO was refined via the Rietveld method: P3[combining macron]1m, a = 5.1318(3) Å, and c = 4.5520(3) Å. Compounds with M = Co and Ni antiferromagnetically order at 11 and 15 K, respectively, whereas the copper compound does not show long-range magnetic order down to 1.5 K. A comparison between the magnetic behavior of the metastable and stable polymorphs was carried out. FeSbO could not be prepared because of the 2Fe + Sb = 2Fe + Sb redox reaction. This electron transfer produces an additional 5s shell for Sb and results in a volume increase. A comparison of the formula volume for the stable mixture FeSbO + 0.5SbO with that extrapolated for FeSbO predicted that the trirutile-type FeSbO can be stabilized at high pressures.
MSbO化合物（M = Mg、Co、Ni、Cu、Zn）以四方三金红石形式存在，其中M = Cu时，由于 Jahn - Teller 效应会发生轻微的单斜畸变。在本研究中，通过钛铁矿型NaSbO与熔融的MSO - KCl（或MgCl - KCl）混合物之间的低温交换反应，首次制备出这五种组分为三方层状蔷薇辉石（PbSbO）型相。加热时，它们会通过非晶态中间体不可逆地转变为已知相，这与之前研究的同结构MnSbO不同，在MnSbO中稳定相与亚稳相在结构上相关。发现相同的方法适用于制备稳定的蔷薇辉石型CdSbO。新相的化学式体积与离子半径具有良好的相关性（M = Cu除外，怀疑其存在 Jahn - Teller 畸变），尽管所有配位数相同，但比已知形式的化学式体积大2 - 3%。通过Rietveld方法对CoSbO的晶体结构进行了精修：P3[combining macron]1m，a = 5.1318(3) Å，c = 4.5520(3) Å。M = Co和Ni的化合物分别在11 K和15 K时发生反铁磁有序，而铜化合物在低至1.5 K时未表现出长程磁有序。对亚稳和稳定多晶型物的磁行为进行了比较。由于2Fe + Sb = 2Fe + Sb氧化还原反应，无法制备FeSbO。这种电子转移为Sb产生了一个额外的5s壳层并导致体积增加。将稳定混合物FeSbO + 0.5SbO的化学式体积与外推得到的FeSbO的化学式体积进行比较，预测三方金红石型FeSbO在高压下可以稳定存在。
