Multiple magnetic transitions and electrical transport transformation of a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>BaFe</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> cubic perovskite single crystal
Yuxuan Liu, Zhehong Liu, Zhi Li, Shijun Qin, Xubin Ye, Xudong Shen, Bowen Zhou, Guanghui Zhou, Stefano Agrestini, Manuel Valvidares, V. Hari Babu, Zhiwei Hu, Youwen Long
Abstract
Cubic perovskite $\mathrm{BaFe}{\mathrm{O}}_{3}$ single crystals with stoichiometric oxygen content were successfully grown by a two-step method. With decreasing temperature, the crystal experiences a spin-glassy transition at ${T}_{\mathrm{SG}}\ensuremath{\approx}181\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, followed by a long-range spiral antiferromagnetic ordering at ${T}_{N}\ensuremath{\approx}117\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, and then a third spin transition at ${T}_{N}^{\ensuremath{'}}\ensuremath{\approx}97\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, revealing the subtle magnetic competition and interactions. As a result, a smaller magnetic field (\ensuremath{\sim}0.4 T) can induce a metamagnetic transition towards a ferromagnetic state with the saturated magnetic moment about $3.2\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}/\mathrm{f}.\mathrm{u}.$ at 2 K. The easy magnetization axis looks to vary from the direction perpendicular to [111] to the [100] axis. Semiconducting behavior with a small activation energy is observed above ${T}_{\mathrm{N}}$, whereas the spiral spin ordering changes the electrical transport to be likely half-metallic with considerable negative magnetoresistance effect.