Magnetization reversal, field-induced transitions andH-Tphase diagram of Y_1-CeCrO₃

We report a systematic study of the magnetic phase diagram in theH-Tplane, negative magnetization (NM), exchange interactions and field-induced spin-flop transitions in the distorted perovskite Y_1-CeCrO₃. Locked AFM and weak-FM configurations in Γ₄(G,F,A) phase of YCrO₃(S= 3/2 ground state) unlocks into the Γ₂(F,G,C;FzR,CxR) phase of the canted AFM and FM structures with the dilute substitution of Ce (x⩾ 0.05). The asymmetric and symmetric exchange interaction (J_AS∼ 0.11 meV andJ_S∼ 0.85 meV) between the trivalent Ce and Cr enable the positive quartic-anisotropy field (HK4∼ 2.85 × 10²Oe) along with the second order anisotropy field (HK2∼ 5.93 × 10²Oe). Unlike the pristine YCrO₃compound, the Ce incorporated system exhibits a giant fourth-order anisotropy constant (K₄= 1.35 × 10⁵erg/c.c.) due to the asymmetric exchange interaction between the trivalent Ce-Cr which further lifts the free energy of the system and causes lag in the onset of AFM ordering showing the significant thermal hysteresis (ΔT∼ 10 K) in the field-cooled (FC)-warming measurement protocol as compared to the FC-cooling mode. The H-T phase diagram, mapped from the isothermal magnetization data and differential magnetic susceptibility data with different measurement protocols clearly distinguishes three prominent regions below theT_N(∼150 K), viz (i) long-range canted AFM + weak FM phase (Γ₄(G,F,A)), (ii) Γ₂₄mixed phase and (iii) robust Γ₂(F,G,C;FzR,CxR) AFM + FM phases. Tunable spin-flopped transition (∼ 30 kOe), significant negative exchange-bias field (H_EB∼ 2.5 kOe), huge coercive field (H_C∼ 22 kOe) and large NM (ΔM∼ 280 emu/mole) are the unique characteristic features of the current investigated system.