A Novel Look at Magnetism in Ni2FeVO6

• Published in: IEEE transactions on magnetics Vol. 58; no. 3; pp. 1 - 10
• Main Authors: Bobrowska, Marta, Typek, Janusz, Leniec, Grzegorz, Zolnierkiewicz, Grzegorz, Filipek, Elzbieta, Prokop, Agnieszka, Blonska-Tabero, Anna
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antiferromagnetism; Clusters; Crystal structure; Electron paramagnetic resonance; Electron spin; Electron spin resonance (ESR); Ferromagnetic phases; Ferromagnetism; Freezing; Ilmenite; Ions; Iron; iron ions; Magnetic fields; Magnetic measurement; Magnetic moments; magnetic properties; Magnetic resonance; Magnetic separation; magnetic spin clusters; Magnetic structure; Magnetism; Magnetometers; Nickel; solid solutions; Spin dynamics; Spin resonance; Temperature dependence
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2022.3142890

DC magnetometry and electron spin resonance (ESR) studies of Ni 2 FeVO 6 powder samples obtained by the traditional calcination method are presented. As our X-ray diffraction study of Ni 2 FeVO 6 has revealed an orthorhombic crystal structure and not previously reported rhombohedral FeTiO 3 -type structure (ilmenite), a new magnetic structure was proposed. As a consequence, the role of magnetic ions had to be re-evaluated. The transition to ferromagnetic (FM)-like phase was found at <inline-formula> <tex-math notation="LaTeX">T_{C} </tex-math></inline-formula> = 200 K in weak magnetic fields, while spin freezing dynamics in the superparamagnetic (SPM) regime was observed below <inline-formula> <tex-math notation="LaTeX">T_{C} </tex-math></inline-formula>. Above 260 K, the Curie-Weiss paramagnetic (PM) phase with a large effective magnetic moment <inline-formula> <tex-math notation="LaTeX">\mu _{\mathrm {eff}} </tex-math></inline-formula> = <inline-formula> <tex-math notation="LaTeX">11.7 ~\mu _{B} </tex-math></inline-formula>/f.u was found. Interestingly, the Griffiths phase (GP) above <inline-formula> <tex-math notation="LaTeX">T_{C} </tex-math></inline-formula> was also detected. The important role of magnetic spin clusters with different sizes has been inferred from magnetization measured in different magnetic fields and at different temperatures. Although the main bulk ferromagnetic phase was not registered in the ESR spectra, they were analyzed in terms of Lorentzian and Gaussian components and attributed to different types of PM spin clusters with FM and antiferromagnetic (AFM) interactions.