Structural, magnetic and magnetocaloric properties of Ag-doped Pr<sub>0.5sub>Sr<sub>0.5-xsub>Ag<sub>xsub>MnO<sub>3sub> manganites (0.0≤x≤0.4)

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• 作者：S. Tarhouni<sup>asup><sup> ; sup><sup>bsup><sup> ; sup><sup>tarhouni.sabrine@ymail.com" class="auth_mail" title="E-mail the corresponding authorsup> ; A. Mleiki<sup>asup><sup> ; sup><sup>bsup> ; I. Chaaba<sup>asup> ; H. Ben Khelifa<sup>asup><sup> ; sup><sup>bsup> ; W. Cheikhrouhou-Koubaa<sup>asup><sup> ; sup><sup>bsup> ; M. Koubaa<sup>asup> ; A. Cheikhrouhou<sup>asup> ; E.K. Hlil<sup>csup>
• 关键词：Manganites ; X-ray diffraction ; Magnetization ; Magnetocaloric effect
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：43
• 期：1
• 页码：133-143
• 全文大小：2214 K

文摘

The effects of partial silver substitution on the structural, magnetic and magnetocaloric properties of Pr<sub>0.5sub>Sr<sub>0.5-m>xm>sub>Ag<sub>m>xm>sub>MnO<sub>3sub> (0.0≤m>xm>≤ 0.4) compounds have been studied. Our powder specimens are synthesized using the sol-gel method at high temperatures. X-Ray diffraction study reveals that all compounds crystallize in the distorted orthorhombic symmetry with Pbnm space group. Magnetization measurements versus temperature under 0.05 T reveal the presence of an antiferromagnetic (AFM) to ferromagnetic (FM) transition at low temperatures for the parent compound, followed by a second one from FM to paramagnetic state (PM). Ag doping is found to reinforce the FM behavior with a Curie temperature (T<sub>Csub>) increasing from 268 (m>xm>=0.0) to 305 K(m>xm>=0.2). However, for higher Ag amount, T<sub>Csub> decreases again from 285 K (m>xm>=0.3) to 170 K (m>x  m>=0.4). The maximum of the magnetic entropy change (mmlsi0005" class="mathmlsrc">mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0272884216316534&_mathId=si0005.gif&_user=111111111&_pii=S0272884216316534&_rdoc=1&_issn=02728842&md5=cf2dcb1f87ac158da37bcb9d24c03969">mg class="imgLazyJSB inlineImage" height="21" width="51" alt="View the MathML source" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0272884216316534-si0005.gif">mathContainer hidden">mathCode"><math altimg="si0005.gif" overflow="scroll"><mrow><mo>-mo><mi>Δmi><msubsup><mrow><mi>Smi>mrow><mrow><mi>Mmi>mrow><mrow><mi>mmi><mi>ami><mi>xmi>mrow>msubsup>mrow>math>) was calculated using the isothermal magnetization curves M (H) under magnetic field change of 5 T and is found to be 4.7 J/(kg K) for m>xm>=0.3. The relative cooling power (RCP) turns out to be 188 J/kg and 229 J/kg for m>xm>=0.0 and m>xm>=0.1, respectively. This suggests that these compounds may be suitable candidates for magnetic refrigeration.