Impact of particle size on the structural and smagnetic properties of superparamagnetic Li-ferrite nanoparticles

Influence of neodymium substitution on structural, magnetic and spectroscopic properties of Ni–Zn–Al nano-ferrites

“…This behavior is called spin canting or non-collinear magnetic order. The Yafet–Kittel angles ( a Y–K ) are calculated from the observed magnetic moment n B values according to the relation below: 63 n B = M B cos α Y–K − M A …”

Structural, Magnetic, and Optical Studies of Ni–Mg Ferrites Synthesized by Polyol Method

“…The difference between these temperatures ( T irr – T B ) implies that the particles in the system are of irregular size and shape and also due to the energy barrier distribution. [ 53 ] The corresponding irreversibility temperature for each system is shown in Table 15.…”

Study of physical properties of a ferrimagnetic spinel Cu1.5Mn1.5O4: spin dynamics, magnetocaloric effect and critical behavior

“…In order to verify the interaction between clusters and their influence on the fluctuation dynamics, different phenomenological models such as Neel–Arrhenius, Vogel–Fulcher and power law are examined. For non-interacting isolated SPM compound, we try to fit the experimental data of the relaxation time ( τ ) vs. freezing temperature ( T f ) by the Néel–Arrhenius law without any critical behavior: 55 where τ 0 is the characteristic time of the system, E a is the activation energy required to overcome the barrier of the reversal of the magnetization, K B is the Boltzmann's constant and T f the freezing temperature. For SPM relaxation, τ 0 depends on the gyromagnetic precession time, usually in the range of ∼10 −10 to 10 −13 s. As indicated in Fig.…”

“…The relaxation behavior in Cu 1.5 Mn 1.5 O 4 compound is described either by spin glass (SG) or by cluster glass (medium interaction). To further distinguish the state of relaxation behavior of copper manganite sample, we used Vogel–Fulcher's law, with an additional term T 0 to deal with the interaction between clusters: 55 whereby T 0 is the characteristic SG transition temperature, which explains the interaction between particles, and its value is between zero and the freezing temperature T f . The parameters τ 0 , E a / K B and T 0 obtained from the best fit of the data in Fig.…”

“…On the other hand, the parameter proposed by Tholence δ Th related to the Vogel–Fulcher method is generally used to identify the type of spin interaction: 55 …”