Spin-glass behavior in ferromagnetic Fe[Fe(CN)6]·xH2O nanoparticles

Mukadam, M. D. ; Kumar, Amit ; Yusuf, S. M. ; Yakhmi, J. V. ; Tewari, R. ; Dey, G. K. (2008) Spin-glass behavior in ferromagnetic Fe[Fe(CN)6]·xH2O nanoparticles Journal of Applied Physics, 103 (12). 123902_1-123902_6. ISSN 0021-8979

Full text not available from this repository.

Official URL: http://jap.aip.org/resource/1/japiau/v103/i12/p123...

Related URL: http://dx.doi.org/10.1063/1.2938837


The magnetic properties of the nanoparticles of hexacyanometallate based molecular magnetic compound Fe[Fe(CN)6].xH2O have been investigated using dc magnetization and the frequency dependent real part of ac susceptibility Xθ c' techniques. The magnetic properties of these nanoparticles with an average particle diameter ~50 nm have been compared with that of the bulk polycrystalline sample. A reduction in the Curie temperature as well as low coercivity and remanent magnetization have been found for the nanoparticles compared to those for the bulk polycrystalline sample. The maximum magnetization for the nanoparticles is also found to be smaller as compared to that for the bulk polycrystalline sample. For the nanoparticles, the peak temperature Tp in the Xθ c' vs T curve has been found to shift to a higher temperature with increasing frequency and this frequency dependence is described well by a power law. The fitting yields the relaxation time constant T0=1.3×10-13 S, the freezing temperature Tg=10.63 K, and the critical exponent zv=5.5± 0.3. For the bulk polycrystalline sample, no such shift in the ac susceptibility peak temperature has been observed. The time dependence of the thermoremanent magnetization has been observed only for the nanoparticles, which could be represented well with a stretched exponential law. The observed magnetic behavior of the nanocrystalline sample indicates the presence of disordered spins (le- ading to a spin-glass behavior) in these ferromagnetically ordered particles.

Item Type:Article
Source:Copyright of this article belongs to American Institute of Physics.
Keywords:Coercive Force; Critical Exponents; Curie Temperature; Ferromagnetic Materials; Iron Compounds; Magnetic Particles; Magnetic Susceptibility; Molecular Magnetism; Nanoparticles; Remanence; Spin Dynamics; Spin Glasses
ID Code:82293
Deposited On:10 Feb 2012 04:50
Last Modified:10 Feb 2012 04:50

Repository Staff Only: item control page