Study of physical properties of a ferrimagnetic spinel Cu_1.5Mn_1.5O₄: spin dynamics, magnetocaloric effect and critical behavior

Abstract

The present work reports a detailed study of the spin dynamics, magnetocaloric effect and critical behaviour near the magnetic phase transition temperature, of a ferrimagnetic spinel Cu1.5Mn1.5O4.

Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni0.6Zn0.4Al0.5Fe1.5O4 Ceramics for High-Temperature Applications

“…Thereby, by combining the value of δ and n , the obtained values of the three critical exponent’s β, γ, and δ were found to be 0.41, 1.0004, and 3.44, respectively. Compared to the expected values of the four theoretical models, the critical exponents obtained from the magnetic entropy change are clearly in agreement with those obtained from the mean field model (β = 0.5, γ = 1, and δ = 3) . This means that there exists a long-range FM order in the Ni–Zn–Al ferrite.…”

“…The scaling hypothesis states that the magnetization ( M ) at T C (which is linked with δ) follows a power law dependence for the second-order phase transition Where D is the critical amplitude.…”

“…Compared to the expected values of the four theoretical models, the critical exponents obtained from the magnetic entropy change are clearly in agreement with those obtained from the mean field model (β = 0.5, γ = 1, and δ = 3). 9 This means that there exists a longrange FM order in the Ni−Zn−Al ferrite. However, the β value obtained is smaller than 0.5, indicating the existence of magnetic inhomogeneities near the temperature of transition.…”

“…Among all these technology applications, magnetic refrigeration application is one of the most promising ones. A large study has been dedicated to ceramic ferrite in the magnetic refrigeration technology (MCE). , It is a cost-effective and environment friendly technology based on the concept of the magnetocaloric effect (MCE) alternative to the conventional gas compression/expansion system. , The MCE is defined as a magneto-thermodynamic phenomenon in which a temperature change in the magnetic material occurs as a result of varying the magnetic field. − MCE is defined as the tendency of a magnetic system to cool down or heat up through a magnetization–demagnetization process . The applied significance of the MCE is easily evaluated and successfully used to reach ultralow temperatures in a research environment .…”