Superspin glass behavior of interacting ferromagnetic nanoparticles in discontinuous magnetic multilayers

Superspin glass behaviour of interacting ferromagnetic nanoparticles in discontinuous magnetic multilayers

Discontinuous magnetic multilayers [Co80Fe20(t)/Al2O3(3nm)]10 with t = 0.9 and 1.0nm are studied by SQUID magnetometry and ac susceptibility. Owing to dipolar interaction the superparamagnetic cluster systems undergo collective glass-like freezing upon cooling. While both samples exhibit very similar glass temperatures Tg ≈ 45 K and critical exponents zν ≈ 10 and γ ≈ 1.4 as obtained from the te...

Interacting ferromagnetic nanoparticles in discontinuous Co80Fe20/Al2O3 multilayers: From superspin glass to reentrant superferromagnetism

Magnetic states of discontinuous Co80Fe20Al2O3 Multilayers

Discontinuous metal–insulator multilayers [Co80Fe20(t)/Al2O3(3 nm)]n were studied by SQUID magnetometry and AC susceptometry. CoFe forms ferromagnetic particles in the Al2O3 matrix. In this paper, we focus on the field dependence of the AC susceptibility of samples with t 1⁄4 1:3 nm. We find strong evidence for transitions from a superparato a superferromagnetic and, finally, to a reentrant sup...

- 1 - Spin glass behavior in an interacting γ - Fe 2 O 3 nanoparticle system

In this paper we investigate the superspin glass behavior of a concentrated assembly of interacting maghemite nanoparticles and compare it to that of canonical atomic spin glass systems. ac versus temperature and frequency measurements show evidence of a superspin glass transition taking place at low temperature. In order to fully characterize the superspin glass phase, the aging behavior of bo...

خواص استاتیک و دینامیک مغناطیسی نانوذرات La0/8Sr0/2MnO3

In this research, nanoparticles of La0.8Sr0.2MnO3 with mean crystallite size of 20 nm have been prepared by sol gel method. The sample has been characterized by X-Ray Diffraction (XRD) using Rietveld refinement, Field Emission Scanning Electron Microscope (FESEM) and Fourier Transform Infrared (FTIR) spectroscopy. The static magnetic properties such as saturation magnetization, effective magnet...