Prediction of optimized magnetocaloric effect in anisotropic zinc ferrite nanoparticles: A Monte Carlo simulation

Hu, Tianyi; Chi, Xiaodan; Lü, Qiang; Yu, Lili; Li, Ruijun; Liu, Yan; Du, An; Li, Zongbin; Shi, Feng; Hu, Yong

doi:10.1016/j.jallcom.2019.06.155

Cited by 9 publications

(5 citation statements)

References 45 publications

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“…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 .…”

Section: Introductionmentioning

confidence: 99%

“…A large study has been dedicated to ceramic ferrite in the magnetic refrigeration technology (MCE). 4,5 It is a costeffective and environment friendly technology based on the concept of the magnetocaloric effect (MCE) alternative to the conventional gas compression/expansion system. 6,7 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.…”

Section: Introductionmentioning

confidence: 99%

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Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

et al. 2022

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This study investigates the magnetic properties of Ni0.6Zn0.4Al0.5Fe1.5O4 ceramics as a function of varying temperature. The results show that the sharp change in magnetization at Curie temperatures produces a reasonable magnetic entropy change (ΔS M). The Ni–Zn–Al ferrite is, therefore, predicted to work better than other spinel ferrites with higher efficiencies. Near the second-order transition, the critical exponents are derived from the magnetic entropy change’s field dependency. Their values are close to the mean field model. The reliability of the calculated exponents is confirmed by using scaling theory. The temperature dependence of the dielectric constants shows the presence of phase transitions. In fact, the local disorder provides a frequency that is dependent on relaxor ferroelectric-like behaviors, which is a significant finding in the search for new lead-free relaxor materials. The modified Curie–Weiss law and the Lorentz and Gaussian-type relationships are used to analyze the diffuse phase transition. A correlation between dielectric and magnetic behaviors near the magnetic phase transition temperature (direct observation magnetodielectric effect) is established. Based on these findings, the Ni0.6Zn0.4Al0.5Fe1.5O4 ceramic appears to be a promising candidate for multifunctional device applications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

et al. 2022

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“…The ferromagnet/antiferromagnet interfacial dipolar constant (D IF ) is unknown experimentally, while it is adjustable by changing the spacer thickness [31,32], and according to the reduced magnetic moment set in the antiferromagnetic layer, a smaller value of D IF compared to D FM is used (D IF = 0.4D FM ), which guarantees induction of exchange bias [34]. We employed the image-sum method in the film plane to avoid the drastic effects produced by truncating dipolar interactions [34,38].…”

Section: Model and Monte Carlo Methodsmentioning

confidence: 99%

Temperature dependence of dipole-induced exchange bias

Lü

Hu²

2020

Nanotechnology

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A modified Monte Carlo method is used to study the dependence of exchange bias, induced by long-range ferromagnet/antiferromagnet interfacial dipolar interactions, on temperature after field cooling. Since sufficient nonzero surplus magnetization in the antiferromagnetic layer is preserved, a positive exchange bias field is yielded. Significantly, this exchange field increases with decreasing temperature and may level off at low temperatures. Then, the antiferromagnetic anisotropy constant, easy-axis direction with respect to the cooling-field direction, antiferromagnetic exchange constant, and antiferromagnetic layer thickness were modulated to study their roles in establishing the low-temperature plateau-like exchange bias field. A thick enough antiferromagnetic layer with the easy-axis direction aligning with the cooling field maximizes the plateau height with a large antiferromagnetic anisotropy constant, while a small antiferromagnetic exchange constant greatly widens the plateau, even from the exchange bias blocking temperature to the lowest temperature. On explicitly calculating the surplus magnetization values in the antiferromagnetic layer meanwhile the dipolar and Zeeman energies in the antiferromagnetic layer, it is found that the ferromagnet/antiferromagnet interfacial dipolar interactions are predominant at the descending branch of the loop to suppress the coercive field with decreasing temperature; in contrast, the magnetic field takes over the lead at the ascending branch and monotonically enhances the coercive field, at the same pace as the decrease in the coercive field at the descending branch. As a consequence, the loop retains a constant shift and becomes wider with decreasing temperature. The long-range noncontact exchange bias that is insensitive to temperature may be used to develop thermal-agitation-resistant spintronic devices with unidirectional anisotropy.

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“…The relationship between MCE and phase transitions implies the anisotropy and exchange energies responsible for the large MCE besides the external magnetic field, and from the energy-saving point of view, the rotary MCE based on the anisotropy contributing to ∆ S M has been developed and studied for the aim of reducing the cost of external magnetic field energy [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. On the other hand, effective methods to control the magnetocaloric properties and their working temperatures (probably around the magnetic phase transition temperature) such as partial substitution [ 22 , 23 ], application of hydrostatic pressure [ 24 ], and hydrogenation [ 25 ] have been proposed.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Magnetocaloric Effect Induced by Continuous Modulation of Exchange Interaction: A Monte Carlo Study

et al. 2022

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A magnetic-to-thermal energy conversion, derived from the continuous modulation of intrinsic exchange energy, is conceived and studied by performing Monte Carlo simulations. On the basis of thermodynamics and Weiss’s molecular field theories, we modified the Maxwell formula, where the magnetic entropy change (∆SM) is calculated by integrating the temperature derivative of magnetization under a continuously increasing exchange interaction, rather than an external magnetic field, from zero to a given value. For the conventional ∆SM induced through increasing magnetic field, the ∆SM maximum value is enhanced with increasing magnetic field, while the ∆SM peak temperature is weakly influenced by the magnetic field. On the contrary, the ∆SM induced by changing the exchange interaction is proportional to the exchange interaction while suppressed by a magnetic field. Another feature is that the relative cooling power calculated from the ∆SM induced by changing the exchange interaction is fully independent of the magnetic field perspective for obtaining the magnetically stabilized self-converted refrigerants. The controlled variation of exchange interaction could be realized by partial substitution or the application of hydrostatic pressure to lower the cost of magnetic energy at no expense of magnetocaloric response, which opens an avenue to develop the practical and energy-saving devices of conversion from magnetic energy to thermal energy, highly extending the material species of the magnetocaloric effect.

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Prediction of optimized magnetocaloric effect in anisotropic zinc ferrite nanoparticles: A Monte Carlo simulation

Cited by 9 publications

References 45 publications

Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

Temperature dependence of dipole-induced exchange bias

Prediction of Magnetocaloric Effect Induced by Continuous Modulation of Exchange Interaction: A Monte Carlo Study

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Prediction of optimized magnetocaloric effect in anisotropic zinc ferrite nanoparticles: A Monte Carlo simulation

Cited by 9 publications

References 45 publications

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

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

Temperature dependence of dipole-induced exchange bias

Prediction of Magnetocaloric Effect Induced by Continuous Modulation of Exchange Interaction: A Monte Carlo Study

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Product

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Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications

Magnetocaloric Effect, Dielectric Relaxor Behavior, and Evidence for Direct Magnetodielectric Behavior in Ni_0.6Zn_0.4Al_0.5Fe_1.5O₄ Ceramics for High-Temperature Applications