Reversal magnetization, spin reorientation, and exchange bias in YCr O3 doped with praseodymium
Abstract
Crystal structure, thermal properties, and magnetic properties were studied systematically in Y1 -xP rxCr O3 with 0.0 ≤x ≤0.3 compositions. Magnetic susceptibility and specific-heat measurements show an increase in the antiferromagnetic transition temperature (TN) as Pr is substituted in the Y sites and notable magnetic features are observed below TN. Strong coupling between magnetic and crystalline parameters is observed in a small range of Pr compositions. A small perturbation in the lattice parameters by a Pr ion is sufficient to induce a spin-reorientation transition followed by magnetization reversal to finally induce the exchange-bias effect. The spin-reorientation temperature (TSR) is increased from 35 to 149 K for 0.025 ≤x ≤0.1 compositions. It is found that the Cr spin sublattice rotates continuously from TSR to a new spin configuration at lower temperature. In addition, magnetization reversal is observed at T*∼35 K for x =0.05 up to T*∼63 K for x =0.20 composition. The M -H curves show a negative exchange-bias effect induced by Pr ions, which are observed below 100 K and are more intense at 5 K. At 10 K, the magnetic contribution of the specific heat as well as the ZFC magnetization show the rise of a peak with increasing Pr content. The magnetic anomaly could be associated with the freezing of the Pr magnetic moment randomly distributed at the 4 c crystallographic site. A clear correspondence between spin reorientation, magnetization reversal, and exchange-bias anisotropy with the tilting and octahedral distortion is also discussed.
- Publication:
-
Physical Review Materials
- Pub Date:
- January 2018
- DOI:
- 10.1103/PhysRevMaterials.2.014409
- arXiv:
- arXiv:1801.04967
- Bibcode:
- 2018PhRvM...2a4409D
- Keywords:
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- Condensed Matter - Materials Science
- E-Print:
- 14 pages, 12 figures, to be published in Physical Review Materials