Temperature-dependent structure and magnetization of YCrO$_3$ compound

TL;DR

This study investigates the temperature-dependent structural and magnetic properties of YCrO$_3$ single crystals, revealing a stable orthorhombic structure, a Néel temperature of 141.58 K, and concurrent antiferromagnetic and weak ferromagnetic phases.

Contribution

It provides detailed insights into the structural stability, magnetic phase transition, and local lattice distortions of YCrO$_3$ across a range of temperatures, with new findings on the simultaneous emergence of antiferromagnetism and weak ferromagnetism.

Findings

No structural phase transition from 36 to 300 K.

Antiferromagnetic transition at 141.58 K.

Concurrent weak ferromagnetism observed below T_N.

Abstract

We have grown a YCrO$_3$ single crystal by the floating-zone method and studied its temperature-dependent crystalline structure and magnetization by X-ray powder diffraction and PPMS DynaCool measurements. All diffraction patterns were well indexed by an orthorhombic structure with space group of $Pbnm$ (No. 62). From 36 to 300 K, no structural phase transition occurs in the pulverized YCrO$_3$ single crystal. The antiferromagnetic phase transition temperature was determined as $T_\textrm{N} =$ 141.58(5) K by the magnetization versus temperature measurements. We found weak ferromagnetic behavior in the magnetic hysteresis loops below $T_\textrm{N}$. Especially, we demonstrated that the antiferromagnetism and weak ferromagnetism appear simutaniously upon cooling. The lattice parameters ($a$, $b$, $c$, and $V$) deviate downward from the Gr$\ddot{\textrm{u}}$neisen law, displaying an anisotropic magnetostriction effect. We extracted temperature variation of the local distortion parameter $\Delta$. Compared to the $\Delta$ value of Cr ions, Y, O1, and O2 ions show one order of magnitude larger $\Delta$ values indicative of much stronger local lattice distortions. Moreover, the calculated bond valence states of Y and O2 ions have obvious subduction charges.