Neutron-diffraction studies of R5Rh4Ge10 (R = Tb, Ho, Er) compounds

Neutron-diffraction patterns recorded in the paramagnetic state confirmed that R5Rh4Ge10 (R = Tb, Ho, Er) compounds exhibit the tetragonal Sc5Co4Si10 (P4/mbm space group)-type of crystal structure. In this structure the rare-earth atoms R occupy three nonequivalent atomic positions. The low-temperature neutron-diffraction data confirm the change of the magnetic structure at Tt=3.8 and at the Néel temperature TN=11.5 K for R = Tb, at TN=7 K for R = Ho, and at Tt=4.2 K and TN=5.5 K for R = Er. In all these compounds the rare-earth moments form complex antiferromagnetic structures: collinear in the case of Tb and Ho compounds, sine-wave-modulated for Er5Rh4Ge10 with the wave vector k= \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\frac\Box1\Box\Box4\Box$\end{document},\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\frac\Box1\Box\Box4\Box$\end{document},0 for 1.5 K<T<4.2 K and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\frac\Box1\Box\Box3\Box$\end{document},\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\frac\Box1\Box\Box3\Box$\end{document},0 for 4.2 K up to TN. The magnetic moment values are different in different sublattices.