View in EDS

Determination of the spontaneous magnetization by analysis of the magnetic entropy change in La0.40Nd0.30Sr0.30Mn0.70Cr0.30O3

Saved in:
Bibliographic Details
Title: Determination of the spontaneous magnetization by analysis of the magnetic entropy change in La0.40Nd0.30Sr0.30Mn0.70Cr0.30O3
Authors: Kallel, Sami1 Sami.Kallel@issatso.rnu.tn, Kallel, Nabil1, Peña, Octavio2, Oumezzine, Mohamed1
Source: Journal of Alloys & Compounds. Aug2010, Vol. 504 Issue 1, p12-15. 4p.
Subjects: Magnetization, Entropy, Perovskite, Phase transitions, Transition temperature, Ferromagnetism
Abstract: Abstract: The magnetic phase transition and magnetic entropy change (−ΔS M ) in the La0.40Nd0.30Sr0.30Mn0.70Cr0.30O3 perovskite were investigated by measuring the magnetization as a function of temperature. The ferromagnetic transition temperature T C and the critical exponents β and γ, determined by analyzing the Arrott plots, are found to be T C =191K, β =0.433, γ =1.053 and δ =3.486. These values for the critical exponents are close to the mean-field values. In order to estimate the spontaneous magnetization M s (T) at a given temperature, we use a process based on the analysis, in the mean-field theory, of the magnetic entropy change (−ΔS M ) versus the magnetization data. An excellent agreement is found between the spontaneous magnetization determined from the entropy change ((−ΔS M ) vs. M 2) and the classical extrapolation from the Arrott curves (μ 0 H/M vs. M 2), thus confirming that the magnetic entropy is a valid approach to estimate the spontaneous magnetization in this system and in other compounds as well. [Copyright &y& Elsevier]
Copyright of Journal of Alloys & Compounds is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Abstract: The magnetic phase transition and magnetic entropy change (−ΔS M ) in the La0.40Nd0.30Sr0.30Mn0.70Cr0.30O3 perovskite were investigated by measuring the magnetization as a function of temperature. The ferromagnetic transition temperature T C and the critical exponents β and γ, determined by analyzing the Arrott plots, are found to be T C =191K, β =0.433, γ =1.053 and δ =3.486. These values for the critical exponents are close to the mean-field values. In order to estimate the spontaneous magnetization M s (T) at a given temperature, we use a process based on the analysis, in the mean-field theory, of the magnetic entropy change (−ΔS M ) versus the magnetization data. An excellent agreement is found between the spontaneous magnetization determined from the entropy change ((−ΔS M ) vs. M 2) and the classical extrapolation from the Arrott curves (μ 0 H/M vs. M 2), thus confirming that the magnetic entropy is a valid approach to estimate the spontaneous magnetization in this system and in other compounds as well. [Copyright &y& Elsevier]
ISSN:09258388
DOI:10.1016/j.jallcom.2010.05.091