Tuning of Cr³⁺ ions doping on the magnetic and magnetocaloric properties of La_0.5Sr_0.5Mn_{1−an style='font-style: italic'>x}Cr_xO₃

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• 作者：C. Shang^a ; ^b ; Z.C. Xia^a ; ^{xia9020@hust.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; M. Wei^a ; ^b ; Z. Jin^a ; ^b ; B.R. Chen^a ; ^b ; L.R. Shi^a ; ^b ; G.L. Xiao^a ; ^b ; S. Huang^a ; ^b
• 关键词：Perovskite manganites ; Doping ; Magnetocaloric effect ; Magnetic entropy change
• 刊名：Physica B: Physics of Condensed Matter
• 出版年：2016
• 出版时间：1 December 2016
• 年：2016
• 卷：502
• 期：Complete
• 页码：39-47
• 全文大小：2733 K

文摘

The effects of Cr³⁺ ions doping on the magnetic and magnetocaloric properties of manganites La_0.5Sr_0.5Mn_1−xCr_xO₃ (x=0.05, 0.1, 0.15, and 0.2) have been investigated. The magnetization measurements show that a ferromagnetic cluster behavior is induced by Cr³⁺ dopants and the paramagnetic to ferromagnetic transition temperature TC decreases from 319 to 251 K with increasing Cr³⁺ content from 0.05 to 0.2. The positive slope of the Arrott plots near T_C indicates a second order phase transition. The magnetic entropy change (−ΔS_M) is estimated from the isothermal magnetization measurements, and the maximum of the magnetic entropy change (−ΔS^max_M) near T_C shows a power law dependence of magnetic field: −ΔS^max_Man id="mmlsi0012" class="mathmlsrc">an class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0921452616303775&_mathId=si0012.gif&_user=111111111&_pii=S0921452616303775&_rdoc=1&_issn=09214526&md5=1177e9f541b69f95a21b127b3d96d412" title="Click to view the MathML source">=mn(μ₀H)an>an class="mathContainer hidden">an class="mathCode">ath altimg="si0012.gif" overflow="scroll">=malse">(μ0Halse">)nath>an>an>an> with n being close to the predicted value ~2/3. The experimental results suggest that the magnetic entropy change and T_C can be tuned by changing the Cr³⁺ ions doping level, which offers an effective method for finding an optimal doping level for magnetic refrigeration near room temperature.