相关论文: Non-equilibrium effects in the magnetic behavior o…
We report detailed studies on magnetic properties of Co3O4 nanoparticles of average size 12.5 nm. Temperature and field dependence of magnetization, wait time dependence of magnetic relaxation (aging), memory effects and temperature…
We report studies on temperature, field and time dependence of magnetization on cupric oxide nanoparticles of sizes 9 nm, 13 nm and 16 nm. The nanoparticles show unusual features in comparison to other antiferromagnetic nanoparticle…
We report studies on temperature, field and time dependence of magnetization on cupric oxide nanoparticles of sizes 9 nm, 13 nm and 16 nm. The nanoparticles show unusual features in comparison to other antiferromagnetic nanoparticle…
Magnetic relaxation in antiferromagnetic CoRh$_2$O$_4$ nanoparticles is investigated at 2 K by cooling the sample from a temperature (70 K) well above the antiferromagnetic ordering temperature at 27 K, following zero field cooled (ZFC) and…
We investigate slow dynamics of collection of a few antiferromagnetic NiO nanoparticles. The zero-field cooled magnetization exhibits size dependent fluctuations. We find memory effects in field cooled magnetization, as well as aging…
The aging and memory effects of Fe$_{3}$O$_{4}$ nanoparticles have been studied using a series of zero-field cooled (ZFC) and field-cooled (FC) magnetization measurements at various aging protocols. The genuine ZFC magnetization after the…
We report about the magnetic properties of antiferromagnetic (AF) MnO nanoparticles (NPs) with different sizes (6-19nm). Using a combination of polarized neutron scattering and magnetometry we were able to resolve previously observed…
A comparative study of the non-equilibrium magnetic phenomena (magnetic blocking, memory, exchange bias and aging effect) has been presented for ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ (CFO) and its composite with non-magnetic BaTiO$_3$…
In this report, the magnetic behaviour of $NiCr_{2}O_{4}$ bulk and nanoparticle samples under different applied magnetic field has been investigated extensively. Nanoparticles of $NiCr_{2}O_{4}$ were obtained by mechanical milling of…
The magnetic behavior of $Fe_{3-x}O_4$ nanoparticles synthesized either by high-temperature decomposition of an organic iron precursor or low-temperature co-precipitation in aqueous conditions, is compared. Transmission electron microscopy,…
We report a systematic study on the structural and magnetic properties of Co_{x}Fe_{3-x}O_{4} magnetic nanoparticles with sizes between $5$ to $25$ nm, prepared by thermal decomposition of Fe(acac)_{3} and Co(acac)_{2}. The large…
The dielectric properties of MnFe$_2$O$_4$ and $\gamma$-Fe$_2$O$_3$ magnetic nanoparticles embedded in insulating matrices were investigated. The samples showed frequency dependent dielectric anomalies coincident with the magnetic blocking…
The field dependence of the peak temperature of the zero-field-cooled (ZFC) magnetization curve of a magnetic nanoparticle system was studied using a diluted magnetic fluid composed of FePt nanoparticles. It is found that the peak…
We report magnetic studies on gelatin coated NiO nanoparticles of average size 7 nm. Temperature and time dependence of dc magnetization, wait time dependence of magnetic relaxation (aging), memory effects in the dc magnetization and…
The effect of an applied magnetic field on the temperature at the maximum of the ZFC magnetization, $M_{ZFC}$, is studied using the recently obtained analytic results of Coffey et al. (Phys. Rev. Lett. {\bf 80}(1998) 5655) for the prefactor…
This work focuses on the microstructure, magnetic properties and magnetocaloric effect of CoFe$_2$O$_4$ (CFO) nanoparticles elaborated by sol-gel auto combustion method. The XRD investigation indicates that CFO is crystallized in a cubic…
The origin of room temperature (RT) ferromagneticlike behavior in ZnO-based diluted magnetic semiconductors is still an unclear topic. The present work concentrates on the appearance of RT magnetic moments in just mixed ZnO/Co3O4 mixtures…
A two dimensional magnetic particle in the presence of an external magnetic field is studied. Equilibrium thermodynamical properties are derived by evaluating analytically the partition function. When the external field is applied…
Magnetic measurements up to 1000 K have been performed on hydrothermally synthesized $\alpha$-Fe$_{2}$O$_{3}$ nanoparticles (60 nm) using a Quantum Design vibrating sample magnetometer. A high vacuum environment (1$\times$10$^{-5}$ torr)…
Thermal activation tends to destroy the magnetic stability of small magnetic nanoparticles, with crucial implications in ultra-high density recording among other applications. Here we demonstrate that low blocking temperature ferromagnetic…