Low temperature neutron diffraction studies on Co(Cr_1−xFe_x)₂O₄ (x = 0.05 and 0.075)

Abstract

We report the magnetic structures of an Fe substituted cobalt chromite system, Co(Cr1−xFex)2O4 (x = 0.05 and 0.075), determined from the analysis of temperature dependent neutron diffraction measurements.

Tuning of multiferroic order with Co doping in CuCr2O4 : Interplay between structure and orbital order

“…For x = 0.8, the M(T ) also changes sign around ≈70 K and it becomes positive below ≈35 K, which is consistent with the previous reports measured at different magnetic fields [25,29]. The FC curve of the compound with x = 0.6 exhibits a change in sign around ≈80 K and remains negative until 2 K. In accordance with the previous reports, these are the usual characteristics of the ferrimagnetically ordered state, where the compensation of magnetization along the magnetic field leads to the change in sign of M(T ) [27,[30][31][32].…”

“…However, a weak change of slope in the ZFC curve may be correlated to the low-T anomaly in (T ), pointing to a magnetoelectric coupling. The low-T anomaly is attributed to the spiral magnetic order, as suggested in the previous reports [25,27,[29][30][31][32]. In Fig.…”

Influence of Fe substitution on multiferrocity and magneto-dielectric properties in CoCr2O4

“…In the case of the FC mode of magnetization measurements, the sample was cooled down from a paramagn etic state to 3 K under the external magnetic field and then the magnetization data was recorded during warming cycle. It clearly reveals the collinear FIM transition at T C ∼ 110 K followed by another peak at 24 K which is related to the magneto-structural transition (T S ) [26,27]. We further observed that the magnetization changes sign at the compensation temper ature, T comp ∼ 44 K. The anomaly at 24 K corresponds to a non-collinear spiral magnetic transition similar to the parent compound CoCr 2 O 4 , as revealed by the neutron diffraction measurements [18,19,27].…”

“…It clearly reveals the collinear FIM transition at T C ∼ 110 K followed by another peak at 24 K which is related to the magneto-structural transition (T S ) [26,27]. We further observed that the magnetization changes sign at the compensation temper ature, T comp ∼ 44 K. The anomaly at 24 K corresponds to a non-collinear spiral magnetic transition similar to the parent compound CoCr 2 O 4 , as revealed by the neutron diffraction measurements [18,19,27]. It is interesting to note that dc-magnetization changes the sign across T comp which was not observed in the pristine compound CoCr 2 O 4 .…”

“…Hence, Fe substituted compounds i.e. Co(Cr 0.95 Fe 0.05 ) 2 O 4 and Co(Cr 0.925 Fe 0.075 ) 2 O 4 tuned the superexchange interaction in such a way that magnetization reversal occurs in the collinear ferrimagnetic region [25][26][27]. The temperature, at which the magnetization goes to zero in the ferrimagnetic state, is called the compensation temperature (T comp ).…”