Magnetic, specific heat and 151Eu Mössbauer studies on compounds

✍ Scribed by Rakesh Kumar; D.S. Rana; C.V. Tomy; P.L. Paulose; R. Nagarajan; C. Min; S.-J. Oh; S.K. Malik

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 110 KB
• Volume: 378-380
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.01.453

✦ Synopsis

Magnetic, 151 Eu Mo¨ssbauer and specific heat measurements have been carried out on Ba 2 EuRu 1Àx Cu x O 6 ð0pxp0:2Þ compounds. From the magnetization data, all the compounds are found to be antiferromagnetically ordered near 40 K, independent of Cu content. A sharp peak at 40 K in the specific heat data also confirms the magnetic ordering. The Eu ions in all the compounds are in the 3+ state as inferred from the 151 Eu Mo¨ssbauer isomer shift values. However, a well split, six line pattern is observed in the 151 Eu Mo¨ssbauer spectra of these compounds below 40 K. This is rather rare for Eu 3þ ð4f 6 ; J ¼ 0Þ which is a nonmagnetic ion. The magnetic hyperfine field at the Eu site is found to be $28 T at 4.2 K and is presumed to arise due to the strong Ru-O-Eu exchange interaction.