Magnetocaloric effect

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 24 4   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 28 3   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 23 4   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 42 2   Download