Magnetocaloric effect

In comparison to the vapour gas-compression refrigeration, magnetic heat-pumping near room-temperature is regarded to be an alternative technology due to its high energy efficiency and environmentally friendly solid-state cooling materials. The magnetic heat pump technology utilizes the magnetic field induced temperature change, which is based on the magnetocaloric effect (MCE).

7p visergeyne 18-06-2024 3 0   Download

This paper assesses recent progress in the development of magnetocaloric microwires and sheds light on the important factors affecting the magnetocaloric behavior and cooling efficiency in microwire systems. Challenges, opportunities, and strategies regarding the development of advanced magnetocaloric microwires are also discussed.

11p vimichaelfaraday 28-12-2023 3 2   Download

The longitudinal-field muon-spin relaxation (LF-mSR) technique was employed to study the spin correlations in (Mn,Fe)2(P,Si) compounds above the ferromagnetic transition temperature (TC). The (Mn,Fe)2(P,Si) compound under study is found to show itinerant magnetism.

5p viberbers 09-08-2023 9 4   Download

A novel class of nanocrystalline/amorphous Gd3Ni/Gd65Ni35 composite microwires were created directly from melt-extraction through controlled solidification. X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) confirmed the formation of a biphase nanocrystalline/amorphous structure in these wires.

8p meyerowitz 25-12-2021 6 0   Download

Research objectives of the thesis: Clarification influence of the elements Na, Sr and Ba substituting for La/Ca and crystal size on the magnetic properties, phase transition and magnetocaloric effects of La0,7Ca0,3MnO3 materials. Found the materials for significant mmagnetocaloric parameters have potential for applications in magnetic refrigeration.Determine the effect of replacing Sr/Ba for Ca in La0,7Ca0,3MnO3 and Co substituting for Mn in La0,7Sr0,3MnO3 on their critical behavior as well as the ferromagnetic interactions order.

31p extraenglish 24-05-2021 19 4   Download

Nd0.6Sr0.4MnO3 sample was fabricated by a solid-state reaction method and its magnetic, magnetocaloric properties were investigated. The Curie temperature, TC, at which a ferromagnetic paramagnetic transition occurred was found to be of about 270 K.

8p tamynhan6 14-09-2020 24 2   Download

In this paper, we present the results of the study of the effect of residual La on crystal structure, magnetic properties of La1+ơFe11.05Si1.95 (ơ= 0.00; 0.03; 0.06 and 0.09) compounds. The analysis of X-ray diffractions showed that when the La content increases to 9, the structure still remains cubic in a typical NaZn13 arrangement with unchanged lattice constant (about 0.5).

6p tamynhan6 14-09-2020 25 2   Download

A thorough analysis on critical exponents around the ferromagnetic-paramagnetic phase transition, using the ArrotteNoakes plots and KouveleFisher method, sheds light on the critical magnetic behavior and its association with the magnetocaloric effect in the Fe-La based alloys.

6p tamynhan4 06-09-2020 9 1   Download

In this paper, we present the results of studying magnetic properties and magnetocaloric effect of Fe90-xPrxZr10 (x = 1, 2 and 3) rapidly quenched alloys. The alloy ribbons with thickness of about 15 µm were prepared by melt-spinning method on a single roller system. X-ray diffraction patterns of the ribbons manifest their almost amorphous structure. Thermomagnetization measurements show that the Curie temperature of the alloys can be controlled to be near room temperature by changing concentration of Pr (x).

7p abcxyz123_02 03-03-2020 20 1   Download

Magnetic properties and giant magnetocaloric effect (GMCE) of Mn-based Heusler compounds such as Co-Mn-Si, Ni-Mn-Sn, Ni-Mn-Sb have been investigated. The results show that the structure strongly influences on magnetic properties and GMCE of these alloys. The coexistence of ferromagnetic (FM) and antiferromagnetic (AFM) orders is observed. The magnetic phase transitions can be controlled by changing composition and annealing condition of the alloys.

8p thuyliebe 12-10-2018 25 1   Download

Study of the effect of Nd substitution for La on magnetocaloric effect (MCE) of polycrystalline perovskites (La1-xNdx)0.7Sr0.3MnO3 (x = 0.0, 0.2 , 0.4, 0.6, 0.8, 1.0 ) is presented. Large MCE is observed in all samples. The presence of Nd affects to both maximum magnetic entropy change, |∆Sm|max, and Curie temperature, TC. |∆Sm|max slightly reduces with low content and increases with high content of Nd and gets maximum value of 4.83 J/kg.K for x = 0.8. TC of the samples determined from the

6p tuanlocmuido 19-12-2012 39 2   Download

Among spinel ferrites, Cd and Zn ferrites are always normal ferrites with Cd and Zn ions locating only in tetrahedral sites. This study presents effect of Zn on the magnetic and magnetocaloric properties of the mixed spinel ferrites Ni1-xZnxFe2O4 (x = 0.60, 0.65, 0.70, 0.75). The presence of Zn affects lattice parameters, saturation magnetization Ms, Curie temperature, Tc, and magnetic entropy change ∆Sm. At highest Zn content, Tc reduces to the temperature lower than room temperature and magnetic structure of spins in the octahedral sublattice should be strongly canted. ...

8p tuanlocmuido 19-12-2012 46 1   Download