Nature of magnetic interactions in β-Co(OH)2 nanoparticles

• Published in: physica status solidi (b) Vol. 253; no. 9; pp. 1795 - 1798
• Main Authors: Gupta, Anu, Tiwari, Surendra Deo, Kumar, Devendra
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.09.2016
• Subjects: magnetization; Nanoparticles; paramagnetism; susceptibility
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201552771

Magnetic properties of β‐Co(OH)2 nanoparticles covering temperature range of 5–300 K in magnetic field upto 50 kG are studied. Zero‐field‐cooled and field‐cooled susceptibility as a function of temperature curves in different applied magnetic fields are seen to bifurcate at Tbf=11K. Curie–Weiss fit of zero‐field‐cooled susceptibility curve well above Tbf yields θ=9K and ionic magnetic moment μ=5.03μB. Magnetization as a function of applied magnetic field curve below Tbf shows a two‐step transition to ferromagnetic state. Strength of three possible exchange interactions among Co2+ ions in β‐Co(OH)2 nanoparticles is also determined. We find that the present system orders antiferromagnetically at TN=11K, with a dominant intralayer ferromagnetic coupling and a weaker interlayer antiferromagnetic coupling.