The orbital effect on the anomalous magnetism and evolution in La$_x$Y$_{1-x}$VO$_3$($0\le x \le 0.2$) single crystals

TL;DR

This study investigates how La doping influences orbital ordering, magnetism, and spin-orbital interactions in La$_x$Y$_{1-x}$VO$_3$ single crystals, revealing stabilization of certain orbital phases and changes in magnetic anisotropy.

Contribution

It provides new insights into the effects of La doping on orbital fluctuations, magnetic anisotropy, and spin-orbital coupling in vanadate crystals.

Findings

La doping stabilizes C-type orbital order and destabilizes G-type orbital order.

Orbital fluctuations decrease with increased La content, affecting magnetic properties.

Strong spin-orbital coupling observed near the Néel temperature in La$_{0.2}$Y$_{0.8}$VO$_3$.

Abstract

The orbital effect on the anomalous magnetism and evolution of low La-doping single crystals, La$_x$Y$_{1-x}$VO$_{3}$ (x = 0, 0.1, and 0.2), has been investigated by applying the X-ray diffraction, specific heat, magnetization and Raman scattering techniques. The larger nearest-neighbor (NN) exchange interaction along c-axis stabilizes the fluctuant G-type orbital ordering (G-OO) which favors the exotic C-type antiferromagnetic order (C-AF). It is found that the NN exchange interaction in ab plane is anisotropy relating to the in plane magnetic anisotropy, which becomes smaller in high La-doped sample. Most interestingly, with increasing the La$^{3+}$ content the orbital fluctuation and hybridization are decreased which stabilizes the C-OO phase and destabilizes the G-OO phase. Meanwhile, the diamagnetism in the exotic C-AF phase becomes weak and the possible mechanism relates to the change of the competition between the single-ion magnetic anisotropy and the Dzyaloshinsky-Moriya (DM) interaction with increasing x. Finally, the strong spin-orbital coupling has been observed at temperature just above T$_N$ in La$_{0.2}$Y$_{0.8}$VO$_{3}$ and a short range spin-orbital correlation is suggested.