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The beryllides MBe13 (M = rare earths and actinides) crystallize in a NaZn13-type cubic structure, which can be categorized as a cage-structured compound. In this study, powder X-ray diffraction measurements have been performed on LaBe13, SmBe13, and UBe13 in the temperature range between 7 and 300 K in order to investigate their crystallographic characteristics systematically. They keep the NaZn13-type cubic structure down to the lowest temperature. We estimated their Debye temperature to be 600 - 750 K from analyses of the temperature dependence of a lattice parameter, being in good agreement with the values reported previously. Rietveld refinements on the obtained powder patterns revealed that the M atom in the 8a site is located in an almost ideal snub cube formed by 24 Be atoms in the 96i site, whose caged structure is unchanged even at the low temperatures. In addition, it is argued from the temperature variation of an isotropic mean-square displacement parameter that the MBe13 compounds commonly have a low-energy phonon mode, which can be described by a model assuming an Einstein oscillation of the M atom with a characteristic temperature of ~ 160 K.
We present the single-crystalline x-ray diffraction study on the Ba4Ru3O10 consisting of the corner-shared Ru3O12 trimers. The crystal structure is re-determined from 78 to 300 K across an antiferromagnetic transition at 105 K. The orthorhombic symme
Single crystals of the Kitaev spin-liquid candidate $alpha$-RuCl$_3$ have been studied to determine low-temperature bulk properties, structure and the magnetic ground state. Refinements of x-ray diffraction data show that the low temperature crystal
The local structure of correlated spin-orbit insulator Sr$_{2-x}$M$_x$IrO$_4$ (M = K, La) has been investigated by Ir L$_3$-edge extended x-ray absorption fine structure measurements. The measurements were performed as a function of temperature for d
We report measurements of structural phase transition of four parent compounds $R$FeAsO ($R$ = La, Sm, Gd, and Tb) by means of low-temperature X-ray diffraction (XRD). Magnetic transition temperatures associated with Fe ions ($T_{N1}$) are also deter
We present an investigation of the influence of structural distortions in charge-carrier doped lmco by substituting La$^{3+}$ with alkaline earth metals of strongly different ionic sizes, that is M = Ca$^{2+}$, Sr$^{2+}$, and Ba$^{2+}$, respectively.