Magnetic compensation effect and phase reversal of exchange bias field across compensation temperature in multiferroic Co(Cr0.95Fe0.05)2O4

Abstract

The multiferroic compound, Co(Cr0.95Fe0.05)2O4, displays reversal in the orientation of magnetic moments along with negative magnetization due to an underlying magnetic compensation phenomenon, which was earlier not noticed in the parent compound of CoCr2O4. This is one of the compounds with spinel structure where the exchange bias field changes sign across the compensation temperature and therefore has the potential attribute to get tuned in a preselected manner. In this letter, we shall elucidate the sign reversal of the exchange bias on the premise of the sign reversal of the magnetic moments, which is confirmed by the specific heat measurements.

Study of exchange bias and training effect in NiCr 2 O 4

“…On the other hand, H C eff is mostly dictated by the domain growth and the associated magnetic anisotropy and it is shown to follow the trend of (111) peak intensity of neutron powder diffraction. Even though EB was observed in other spinel chromites especially upon impurity substitutions such as Co(Cr 0.95 Fe 0.05 ) 2 O 4 and Cu 1-x Zn x Cr 2 O 4 (x ¼ 0.1, 0.3) [36,37], the nature of EB in the present sample is quite different. The EB observed in Cu 1-x Zn x Cr 2 O 4 (x ¼0.1, 0.3) is mainly due to the freezing effect of the random anisotropy.…”

First-principles investigations into the thermodynamics of cation disorder and its impact on electronic structure and magnetic properties of spinel Co(Cr1–xMnx)2O4

“…The richness of it's magnetic phase diagram comprising of various long range and short-range, collinear and non-collinear magnetic structures [24][25][26][27] prompted researchers to examine the effects of substitution of one of the magnetic atom with a new one on it's properties. Subsequently, new and interesting phenomena like tunable Exchange Bias, temperature dependent magnetic compensation and magnetostrictions were observed upon controlled substitution of Cr with Fe atoms [28][29][30][31] . These novel phenomena were attributed to the composition dependent occupancy pattern of the substituted Fe atoms in CoCr 2 O 4 which violated the empirical idea of expected occupancy pattern obtained from Mossbauer experiments 32 and also from the theoretical model based upon the relative sizes of cations 33 .…”

Magnetization reversal induced by Mn substitution in spinel chromite NiCr2O4

“…This is because the magnetic anisotropy needs to be strong enough to prevent the flipping spins from aligning with the applied magnetic field . Recently, the MR has been observed in spinel chromite CoCr 2 O 4 by Cu substitution in Co‐site or Fe substitution in Cr‐site . The competition of the 2 magnetic sublattices is considered to be responsible for the phenomenon.…”

“…3 Recently, the MR has been observed in spinel chromite CoCr 2 O 4 by Cu substitution in Co-site or Fe substitution in Cr-site. 15,16 The competition of the 2 magnetic sublattices is considered to be responsible for the phenomenon. It has greatly attracted our attention since the magnitude of the sublattice magnetization could effectively be tuned through transition metals substitution.…”