Back to Search
Start Over
Comparison of the nature of magnetism in α-Ni(OH)2 and β-Ni(OH)2.
- Source :
- Journal of Applied Physics; May2010, Vol. 107 Issue 9, p09B511-1-09B511-3, 3p
- Publication Year :
- 2010
-
Abstract
- For the two stable phases of Ni(OH)<subscript>2</subscript>, viz. α-Ni(OH)<subscript>2</subscript> and β-Ni(OH)<subscript>2</subscript>, structural and magnetic properties are compared employing x-ray diffraction (XRD), scanning electron microscopy/transmission electron microscopy (TEM/SEM), and variation of the magnetization (M) with temperatures (2-350 K) and magnetic fields (up to ≈65 kOe). Both phases crystallize in the layered hexagonal structure with a=3.04 Å (3.12 Å) and c=23.6 Å (4.67 Å) for the α(β) phase with clear evidence for turbostraticity in the α-phase. From TEM/SEM, the β-phase consists of nanoplates of dimensions 30(10)×3(1) nm, whereas the α-phase has flowerlike morphology with petal thickness ≈5(1) nm. The low-field M versus T data for the zero-field-cooled/field cooled cases bifurcates at Tp=25 K (13 K) for the β(α) phase. For T>Tp, Curie-Weiss variation of M versus T is observed yielding positive θ=20.6 K (32 K) with μ=2.95 μB (3.13 μB) for the Ni<superscript>2+</superscript> ions in the β(α) phase. The M versus H data at 2 K shows antiferromagnetic (ferromagnetic) like variation for the β(α) phase with dM/dH showing peaks at Hc1=28 kOe and Hc2=55 kOe for the β-phase. It is concluded that β-Ni(OH)<subscript>2</subscript> is a metamagnet for T<TN=25 K, whereas α-Ni(OH)<subscript>2</subscript> is a hard ferromagnet with Tc=13 K and domain structure for H<5 kOe. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 107
- Issue :
- 9
- Database :
- Complementary Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 98309621
- Full Text :
- https://doi.org/10.1063/1.3358015