Magnetization reversal and Yb3+/Cr3+ spin ordering at low temperature for perovskite YbCrO3 chromites

Abstract

The temperature dependence of the dc magnetization and the specific heat capacity are systematically investigated for the perovskite YbCrO3 chromites. The results show that there exist two complex sequences of magnetic transitions with the characteristics of magnetization reversal and Yb3+/Cr3+ spin ordering at different temperature, respectively. The antiferromagneticlike transition around TN=118 K is attributed to the antiferromagnetic ordering of the Cr3+ spins and a negative magnetization, accompanied with a tendency to the plateau below 10 K caused by the Yb3+ ordering. We obtain the Weiss constant of −197.0 K and an effective moment of 5.99μB for the sum of the free ion values of 4.53μB for Yb3+ and 3.87μB for high-spin Cr3+ from the experiments, which shows an antiferromagnetic interaction and the existence of weak canted antiferromagnetic (CAFM) characteristics. Corresponding to the magnetic phase transition in the Cr sublattice, the specific heat capacity under zero fields exhibits a sharp λ-shape peak near temperature TN, which is depressed and broadened smoothly with the increase in the magnetic field. And a shoulder-shaped Schottky-type anomaly below 12 K is observed in the specific heat capacity curves. This can be interpreted by accounting for the molecular field approximation by assuming that the induced polarization of the paramagnetic ytterbium ions is opposite to the ferromagnetic moment of the chromium ions. According to the results of the zero fields cooling and the field cooling magnetization, the possible existence of spin ordering for the Yb3+ moments can be predicted.

Zero-field cooled exchange bias effect in La Sm1−CrO3 (x=0–0.9) ceramics

“…A superimposed magnetization from Sm 3 þ and Cr 3 þ [ Fig. 4(a)] is observed in the magnetization-temperature curves [16,25]. The magnetic irreversible region between T SR and T N will be reasonable for the H EB detected above T SR , because of the coexistence of weak FM and AFM components.…”

“…Recently, spontaneous magnetic anisotropy induced by spin reorientation causes renewed interests in rare-earth orthochromites [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The compounds RCrO 3 (R ¼La-Lu, and Y) crystallize in orthorhombic distorted perovskite structure with four formula units per unit cell [27].…”

Origin of the magnetization and compensation temperature in rare-earth orthoferrites and orthochromates

“…Further, the coupling in Eq. (2) renders a picture in which the magnetic ordering of the M spins and the oxygen octahedral tilting work together to create an effective magnetic field, B R eff , acting on the rare-earth sublattice and given by 31,33,35 ) the net magnetization vanishes at a specific compensation temperature, T comp . This effect has been attributed to the fact that, below a certain temperature, the R ions acquire a magnetization that is opposite to that of the Fe/Cr sublattice and grows faster than the one of the B ions when further decreasing the temperature, 26,27 as suggested by the relatively large paramagnetic susceptibility of the R spins.…”

Studies on multifunctional behaviour of Cr doped SrWO4 Compounds

“…The unsaturated ferromagnetic behaviour observed for 20 % Cr doped samples till 12,500 Oe reveals the signature of antiferromagnetic ordering and ascribed to the increase in number of Cr 3? ion into SrWO 4 system [57][58][59]. According to Ruderman-Kittel-Kasuya-Yosida (RKKY) theory, the substitution of Cr 3?…”