Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄
Attempts to unravel the nature of magnetic ordering in LaSrCoO4 (Co3+), a compound intermediate between antiferromagnetic (AFM) La2CoO4 (Co2+) and ferromagnetic (FM) Sr2CoO4 (Co4+), have met with limited success so far. In this paper, the results of a thorough investigation of dc magnetization and a...
| Main Authors: | , , , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
2023
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| Online Access: | https://hdl.handle.net/10356/171708 |
| _version_ | 1811692395611291648 |
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| author | Ahad, Abdul Gautam, K. Majid, S. S. Dey, K. Tripathy, A. Rahman, F. Choudhary, R. J. Sankar, R. Sinha, A. K. Kaul, S. N. Shukla, D. K. |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Ahad, Abdul Gautam, K. Majid, S. S. Dey, K. Tripathy, A. Rahman, F. Choudhary, R. J. Sankar, R. Sinha, A. K. Kaul, S. N. Shukla, D. K. |
| author_sort | Ahad, Abdul |
| collection | NTU |
| description | Attempts to unravel the nature of magnetic ordering in LaSrCoO4 (Co3+), a compound intermediate between antiferromagnetic (AFM) La2CoO4 (Co2+) and ferromagnetic (FM) Sr2CoO4 (Co4+), have met with limited success so far. In this paper, the results of a thorough investigation of dc magnetization and ac susceptibility in single-phase LaSrCoO4 provide clinching evidence for a thermodynamic paramagnetic (PM)-ferromagnetic (FM) phase transition at T-c = 220.5 K, followed at lower temperature (T-g = 7.7 K) by a transition to the cluster spin glass state (CSG). Analysis of the low-field Arrott plot isotherms, in the critical region near Tc , in terms of the Aharony-Pytte scaling equation of state clearly establishes that the PM-FM transition is basically driven by random magnetic anisotropy (RMA). For temperatures below similar to 30 K, large enough RMA destroys long-range FM order by breaking up the infinite FM network into FM clusters of finite size and leads to the formation of a CSG state at temperatures T <= 8 K by promoting freezing of finite FM clusters in random orientations. Increasing strength of the single-ion magnetocrystalline anisotropy (and hence RMA) with decreasing temperature is taken to reflect an increase in the number of low-spin Co3+ ions at the expense of that of high-spin Co3+ ions. At intermediate temperatures (30 K <= T <= 180 K), spin dynamics has contributions from the infinite FM network (fast relaxation governed by a single anisotropy energy barrier) and finite FM clusters (extremely slow stretched exponential relaxation due to hierarchical energy barriers). |
| first_indexed | 2024-10-01T06:35:06Z |
| format | Journal Article |
| id | ntu-10356/171708 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:35:06Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | ntu-10356/1717082023-11-06T15:35:27Z Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ Ahad, Abdul Gautam, K. Majid, S. S. Dey, K. Tripathy, A. Rahman, F. Choudhary, R. J. Sankar, R. Sinha, A. K. Kaul, S. N. Shukla, D. K. School of Physical and Mathematical Sciences Science::Physics Cluster Glass Spin-state Attempts to unravel the nature of magnetic ordering in LaSrCoO4 (Co3+), a compound intermediate between antiferromagnetic (AFM) La2CoO4 (Co2+) and ferromagnetic (FM) Sr2CoO4 (Co4+), have met with limited success so far. In this paper, the results of a thorough investigation of dc magnetization and ac susceptibility in single-phase LaSrCoO4 provide clinching evidence for a thermodynamic paramagnetic (PM)-ferromagnetic (FM) phase transition at T-c = 220.5 K, followed at lower temperature (T-g = 7.7 K) by a transition to the cluster spin glass state (CSG). Analysis of the low-field Arrott plot isotherms, in the critical region near Tc , in terms of the Aharony-Pytte scaling equation of state clearly establishes that the PM-FM transition is basically driven by random magnetic anisotropy (RMA). For temperatures below similar to 30 K, large enough RMA destroys long-range FM order by breaking up the infinite FM network into FM clusters of finite size and leads to the formation of a CSG state at temperatures T <= 8 K by promoting freezing of finite FM clusters in random orientations. Increasing strength of the single-ion magnetocrystalline anisotropy (and hence RMA) with decreasing temperature is taken to reflect an increase in the number of low-spin Co3+ ions at the expense of that of high-spin Co3+ ions. At intermediate temperatures (30 K <= T <= 180 K), spin dynamics has contributions from the infinite FM network (fast relaxation governed by a single anisotropy energy barrier) and finite FM clusters (extremely slow stretched exponential relaxation due to hierarchical energy barriers). Published version S.S.M. acknowledges the financial support from SERB, India, in the form of the national postdoctoral fellowship (NPDF) award (No. PDF/2021/002137). R.S. acknowledges the financial support provided by the Ministry of Science and Technology in Taiwan under Projects No. MOST-111-2124-M-001-009, No. MOST-110-2112-M-001- 065-MY3, and No. AS- iMATE-111-12. 2023-11-06T02:38:43Z 2023-11-06T02:38:43Z 2020 Journal Article Ahad, A., Gautam, K., Majid, S. S., Dey, K., Tripathy, A., Rahman, F., Choudhary, R. J., Sankar, R., Sinha, A. K., Kaul, S. N. & Shukla, D. K. (2020). Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄. Physical Review B, 107(21), 214405-. https://dx.doi.org/10.1103/PhysRevB.107.214405 1098-0121 https://hdl.handle.net/10356/171708 10.1103/PhysRevB.107.214405 2-s2.0-85163564603 21 107 214405 en Physical Review B © 2023 American Physical Society. All rights reserved. This article may be downloaded for personal use only. Any other use requires prior permission of the copyright holder. The Version of Record is available online at http://doi.org/10.1103/PhysRevB.107.214405 or URL link. application/pdf |
| spellingShingle | Science::Physics Cluster Glass Spin-state Ahad, Abdul Gautam, K. Majid, S. S. Dey, K. Tripathy, A. Rahman, F. Choudhary, R. J. Sankar, R. Sinha, A. K. Kaul, S. N. Shukla, D. K. Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title | Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title_full | Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title_fullStr | Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title_full_unstemmed | Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title_short | Random magnetic anisotropy driven transitions in layered perovskite LaSrCoO₄ |
| title_sort | random magnetic anisotropy driven transitions in layered perovskite lasrcoo₄ |
| topic | Science::Physics Cluster Glass Spin-state |
| url | https://hdl.handle.net/10356/171708 |
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