Sign reversal of both spontaneous and conventional exchange bias in nanoparticles of Y2FeCrO6 double perovskite

Abstract

Single-phase nanoparticles sample of Y2FeCrO6 double perovskite with an average particle size of 67 nm was prepared and its structural and magnetic behavior is reported. Magnetization vs temperature (M–T) study revealed that the Neel temperature, TN is 327 K, which is greater than the previous finding [Maiti et al., J. Phys. D: Appl. Phys. 46, 415303 (2013)]. Super-exchange interactions in Cr3+–O–Cr3+ and Fe3+–O–Fe3+ networks are responsible for AFM transition. Magnetization reversal (MR) with a high compensation temperature Tcomp = 192 K and sign reversal in both spontaneous and conventional exchange bias fields are observed. In addition, a spin reorientation is observed at TSR ∼ 30 K. At 5 K, a zero-field cooled spontaneous exchange bias (SEB) field of 265 Oe is observed. At the same temperature, after field cooling the sample at 0.5 T, the maximum value of the exchange bias field (CEB) is found to be 2.1 kOe. The SEB shows a sign reversal across TSR, and the CEB reverses its sign across Tcomp. The observed thermal hysteresis of magnetization indicates a first-order phase transition. The loop width of magnetic hysteresis as a function of magnetization exhibits a double peak confirming the multiple magnetic phase behavior. Bipolar switching of magnetization has been demonstrated at 50 K. The competition between single-ion anisotropy and Dzyaloshinsky–Moriya interaction is responsible for the above behaviors.