Point Defects in Rare-Earth Perovskite Systems BaMO 3 ( M = Ce, Pr and Tb) on Dielectric and Magnetic Behaviors

AbstractThis study focused on the rare-earth hetero-valent substituted perovskite BaMO3 (M = Ce, Pr and Tb) which expected to show magnetoelectric response. In general, diamagnetic feature is presented in the 4f 0 BaCeO3 system down to 2 K which is chosen as a reference in the study while BaPrO3 (4f 1) and BaTbO3 (4f 7) display antiferromagnetic phase transition at TN = 11.7 and 33.2 K, respectively, measured by MPMS magnetometer. At high oxygen partial pressure and donor ion-substitution (Nb5+), the BaMO3 systems demonstrate a similar defect chemistry to titanate perovskite which compensated by Ba-vacancy. Dielectric relaxation is detected for the doublet (BaPrO3 and BaTbO3) at the antiferromagnetic phase transition region. In order to examine the magnetoelectric response, the 8 Tesla of magnetic field is applied to the samples during the dielectric measurement. BaTbO3 shows a modest magnetoelectric response around 0.2% at the antiferromagnetic phase transition while that of BaPrO3 is silent. The activation energies derived from Arrhenius equation are reported to be in the range of 0.2 − 0.6 eV.Keywords: Rare-earth perovskitepoint defectmagnetoelectric AcknowledgmentsW’e would like to thank our colleagues, Dr. Usa Sukkha, for the helpful support in this research.Disclosure StatementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported financially by KMITL under Grant No. KREF116501. The work of Phieraya Pulphol was supported financially by King Mongkut’s Institute of Technology Ladkrabang (KMITL) under Grant No. KREF146503. The work of T. Bongkarm was supported by Naresuan University (NU) and National Science, Research and Innovation Fund (NSRF) with Grant No. R2566B002.