Anomalous room temperature magnetoresistance in brownmillerite Ca2Fe2O5

作者:Dhankhar Suchita; Gupta Kapil; Bhalerao Gopal; Shukla Neeraj; Chandran Maneesh; Francis Bellarmine; Tiwari Brajesh; Baskar K; Singh Shubra*
来源:RSC Advances, 2015, 5(112): 92549-92553.
DOI:10.1039/c5ra16955k

摘要

We demonstrate the hitherto unreported field induced magnetoresistance in wet chemical synthesized bulk polycrystalline brownmillerite Ca2Fe2O5. A magnetoresistance of 12% is observed at room temperature, well below its antiferromagnetic transition temperature of 775 K. The variation in resistivity with increasing and decreasing magnetic field shows a significant memory effect. When synthesized in a nanostructured form it exhibits weak ferromagnetism due to the appearance of an Fe oxide phase, besides exhibiting a shift to a higher antiferromagnetic Neel temperature of 820 K. Spectroscopic investigations (X-ray photoelectron and Raman spectroscopy) as well as magnetic measurements have been employed to investigate the above behavior of brownmillerite Ca2Fe2O5.

  • 出版日期2015