Magnetic properties of RE0.7Ca0.3Mn0.95Fe0.05O3 (RE=Sm and Gd) manganites at low temperature

作者：Abdel Khalek E K^*; Salem A F; Mohamed E A; Bahgat A A

来源：Journal of Magnetism and Magnetic Materials, 2010, 322(8): 909-914.

DOI：10.1016/j.jmmm.2009.11.023

• Perovskite
• Manganite
• Mossbauer effect
• VSM
• Low temperature

The magnetic properties of RE0.7Ca0.3Mn0.95Fe0.05O3 perovskite with rare-earth cations (RE=Sm and Gd) were investigated by means of X-ray diffraction, Mossbauer spectroscopy, and low temperature (4.2-266K) magnetization measurements. Structural characterization of these compounds shows that they both have orthorhombic (Pbnm) structure. The Mossbauer spectra show clear evidence of local structural distortion of the Mn(Fe)O-6 octahedron, which is based on the non-zero nuclear quadrupole interactions for high-spin Fe3+ ions. It was found that the local structural distortion increases significantly when Sm3+ is replaced by Gd3+. This distortion is attributed to the Jahn-Teller coupling strength as estimated from the Mossbauer effect results. The magnetic results indicate that the Curie temperature decreases as a result of replacing Sm by Gd. This is due to the decrease of the average A-site cationic radius <r(A)>. The rapid increase of magnetization at low temperature indicates the magnetic ordering of rare earth ions at the A-site.

• 出版日期2010-4
• 单位中国石油大学（北京）