Study of Exchange Bias Effect in LaCr1−xRuxO3 (0 ≤ x ≤ 0.3)

Abstract

The interfacial exchange interaction is key to realize exchange bias (EB) phenomenon in  materials consisting of two different magnetic phases, which have immense applications in modern era technological development. LaCrO₃ (LCO) is an antiferromagnetic (AFM) oxide, which could be utilized to perceive near room-temperature exchange bias phenomenon. In this work, we report an experimental investigation on the structural, magnetic and dielectric properties of LaCr_1−xRu_xO₃ (0 ≤ x ≤ 0.3) through x-ray diffraction, x-ray photoelectron spectroscopy and temperature- and field-dependent magnetization and dielectric measurements. All samples are found to be crystallized in the orthorhombic structure with space group Pnma, and cell volume reveals a usual ionic radius related enhancement due to Ru⁴⁺ ion doping. The AFM transition of pure LCO is modified to ferromagnetic-like (FM-like) transition; while, transition temperature continuously decreases with increase in Ru doping concentration. Magnetization measurements indicate the formation of ferromagnetic cluster-glass state in x = 0.2 sample. We find that a tenfold increase in coercivity value for x = 0.1 as compared to x = 0, suggesting the evolution of moderate FM component. Interestingly, complex interfacial exchange interaction between host AFM matrix of LCO and induced FM phase leads to a significant EB phenomenon in the doped samples. The values of \(\left|{H}_{EB}\right|\) are found to be 2.61 kOe and 1.62 kOe at 200 K for x = 0.1 and x = 0.2, respectively. Moreover, EB effect can be tuned by varying the concentration of Ru dopants in LCO, which is fascinating from technological perspectives.