Hot off the press: Ma and Martí’s work published in JMMM!

Members on N&N Group have published yet another article in recent days. The paper “Magnetic properties of Cr-substituted ε-(Fe_1-xCr_x)₂O₃ nanoparticles with epsilon structure” authored by Ma Zheng and Martí Gich was published in the Journal of Magnetism and Magnetic Materials. 

The work has been carried out in ICMAB and at ALBA synchrotron. The authors reported the successful substitution of significant amounts of Fe³⁺ by Cr³⁺ (up to 7.5 atomic %) into the polar ferrimagnet ε-Fe₂O₃ which has received considerable attention for its unusually large magnetic anisotropy and magnetoelectric multiferroic properties at room-temperature. The results make way for gaining a deeper understanding of the origins of magnetocristalline anisotropy and magnetoelastic effects in ε-Fe₂O₃ and thus of its properties (huge coercivity and magnetoelectric properties), which are relevant to the prospective applications in the field of information technologies.

Abstract:

ε-Fe₂O₃ has gained considerable interest due to its intriguing properties and great application potentials. In this work ε-(Fe_1−xCr_x)₂O₃ (x= 0, 0.03, 0.075) nanoparticles encapsulated in silica have been successfully prepared by sol–gel chemistry. Synchrotron diffraction confirms that the polar Pna2₁ structure of ε-Fe₂O₃ is robust against the substitution of Fe by Cr. The incorporation of chromium is accompanied by a softer magnetic behaviour, and also a gradual decrease in the ferromagnetic signal associated to the super-hard FM2 ferrimagnetic phase. While the Cr substitution has little impact on the low temperature incommensurate transition, it is found that Cr substitution shifts the super-hard and soft ferrimagnetic transitions (respectively, T_N2 and T_N1) to notably lower temperatures.