Study on the magnetic properties and critical behavior of CoFe2−xAlxO4(x= 1.0 and 1.2) spinel ferrite

Autor: Song, Zonghao, Cao, Ruiyang, Ruan, ChenLiang, Zhang, Xian, Wang, Shouguo, Wang, Meiling, Ma, Yongqing, Zheng, Ganhong
Zdroj: International Journal of Materials Research: Zeitschrift fuer Metallkunde; August 2024, Vol. 115 Issue: 8 p610-622, 13p
Abstrakt: We have examined the behavior of CoFe2−xAlxO4(x= 1.0 and 1.2) ferrite close to the transition from ferromagnetic to paramagnetic phases (TC). The findings indicate that at a temperature of TC= 314 K (x= 1.0) and TC= 224 K (x= 1.2), there is a second order magnetic phase transition. We used various methods, including modified Arrott plot, Kouvel–Fisher method, and critical isotherm analysis, to determine the critical exponents which were found to be similar to those expected for the Tricritical Mean-field model (β= 0.288, γ= 1.057, and δ= 4.665) for the x= 1.0 sample. The critical exponents for the x= 1.2 sample (β= 0.771, γ= 1.081, and δ= 2.403) belonged to a different universality class. These results suggest that the replacement of Fe ions with non-magnetic Al ions decreases the Co–Fe, Fe–Fe, Co–Co interaction sites in the CoFe2O4spinel ferrite, increasing magnetic disorder.
Databáze: Supplemental Index