Slow dynamics of interacting antiferromagnetic nanoparticles

Abstract

We study magnetic relaxation dynamics, memory and aging effects in interacting polydisperse antiferromagnetic NiO nanoparticles by solving a master equation using a two-state model. We investigate the effects of interactions using dipolar, Nearest-Neighbour Short-Range (NNSR) and Long-Range Mean-Field (LRMF) interactions. The magnetic relaxation of the nanoparticles in a time-dependent magnetic field has been studied using LRMF interaction. The size-dependent effects are suppressed in the ac-susceptibility, as the frequency is increased. We find that the memory dip, that quantifies the memory effect is about the same as that of non-interacting nanoparticles for the NNSR case. There is a stronger memory-dip for LRMF, and a weaker memory-dip for the dipolar interactions. We have also shown a memory effect in the Zero-field-cooled magnetization for the dipolar case, a signature of glassy behaviour, from Monte-Carlo studies.

14 pages, 9 figures

References in corpus (10)

• Aging and Memory Effects in Superparamagnets and Superspin Glasses
• Signatures of Spin Glass Freezing in NiO Nanoparticles
• Monte Carlo simulation with time step quantification in terms of Langevin dynamics
• Collective states of interacting ferromagnetic nanoparticles
• Memory in nanomagnetic systems: Superparamagnetism versus Spinglass behavior
• Non-equilibrium dynamics in an interacting nanoparticle system
• Models for the magnetic ac susceptibility of granular superferromagnetic CoFe/Al${}_2$O${}_3$
• A Comment on "Memory Effects in an Interacting Magnetic Nanoparticle System"
• Relaxation dynamics of stochastic long-range interacting systems
• Memory and aging effects in antiferromagnetic nanoparticles

Cited by in corpus (1)

• Spin torque antiferromagnetic nanooscillator in the presence of magnetic noise