Crystal field investigation in the light rare earth R$_3$Pt$_{23}$Si$_{11}$ compounds

R. M. Galéra; C. Opagiste; M. Amara; J. C. Toussaint; M. B. Lepetit; S. Rols

paper

Crystal field investigation in the light rare earth R $_{3}$ Pt $_{23}$ Si $_{11}$ compounds

arXiv:1612.03681

Abstract

The crystalline electric field (CEF) is investigated in Pr $_{3}$ Pt $_{23}$ Si $_{11}$ and Nd $_{3}$ Pt $_{23}$ Si $_{11}$ by neutron spectroscopy (NS). At low temperature, the number of observed CEF excitations is consistent with the orthorhombic symmetry at the rare earth site. This agrees with previous results on Ce $_{3}$ Pt $_{23}$ Si $_{11}$ . For Pr- and Nd $_{3}$ Pt $_{23}$ Si $_{11}$ , the number of CEF parameters is too large to allow for an unambiguous determination. This determination is possible for Ce $_{3}$ Pt $_{23}$ Si $_{11}$ , due to a reduced number of parameters and to the availability of extensive experimental data. A specific procedure is developed for this purpose that combines genetic algorithmics and optimization methods. An unique set of CEF parameters is found for Ce $_{3}$ Pt $_{23}$ Si $_{11}$ . It reveals a strong anisotropy at the orthorhombic site, responsible for an easy threefold magnetization axis in the cubic system. Using a microscopic, mean-field, description, the magnetization processes in the paramagnetic and ferromagnetic phases of Ce $_{3}$ Pt $_{23}$ Si $_{11}$ are well reproduced. Ce $_{3}$ Pt $_{23}$ Si $_{11}$ is shown to realize a model for systems where conflicting anisotropies are forced to cooperate.

8 pages, 11 figures

Crystal field investigation in the light rare earth R3​Pt23​Si11​ compounds

Abstract

Crystal field investigation in the light rare earth R $_{3}$ Pt $_{23}$ Si $_{11}$ compounds