Author:
Al-Mamari R. T.,Widatallah H. M.,Elzain M. E.,Gismelseed A. M.,Al-Rawas A. D.,Al-Harthi S. H.,Myint M. T. Z.,Al-Saqri N.,Al-Abri M.
Abstract
AbstractThe core and surface structure and magnetic properties of mechano synthesized LaFeO3 nanoparticles (30–40 nm), their Eu3+-doped (La0.70Eu0.30FeO3), and Eu3+/Cr3+ co-doped (La0.70Eu0.30Fe0.95Cr0.05O3) variants are reported. Doping results in a transition from the O′-type to the O-type distorted structure. Traces of reactants, intermediate phases, and a small amount of Eu2+ ions were detected on the surfaces of the nanoparticles. The nanoparticles consist of antiferromagnetic cores flanked by ferromagnetic shells. The Eu3+ dopant ions enhance the magnetization values relative to those of the pristine nanoparticles and result in magnetic susceptibilities compatible with the presence of Eu3+ van Vleck paramagnetism of spin–orbit coupling constant (λ = 363 cm−1) and a low temperature Curie–Weiss like behavior associated with the minority Eu2+ ions. Anomalous temperature-dependent magnetic hardening due to competing magnetic anisotropy and magnetoelectric coupling effects together with a temperature-dependent dopant-sensitive exchange bias, caused by thermally activated spin reversals at the core of the nanoparticles, were observed.
Publisher
Springer Science and Business Media LLC
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