Antiferromagnetic to ferromagnetic phase transition as a transition to partial ordered spins. Application to $La_{1-x}Ca_xMnO_3$ in the doping range $x\geq 0.50$
Fuente:
arXiv
Enregistré dans:
| Auteur principal: | |
|---|---|
| Format: | Preprint |
| Publié: |
2024
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866909319802388480 |
|---|---|
| author | Karchev, N. |
| author_facet | Karchev, N. |
| contents | Magnetic state is a partial ordered state if only part of the electrons in the system give contribution to the magnetic order.
We study Heisenberg model of two sublattice spin system, on the body-centered cubic lattice, with antiferromagnetic nearest neighbors exchange of sublattice A and B spins
and two different ferromagnetic exchange constants for sublattice A ($J^A$) and B ($J^B$) spins. When $J^A>J^B$ the system undergoes transition from
paramagnetism to ferromagnetism at Curie temperature $T_C$. Only the sublattice A spins give contribution to the magnetization of the system.
Upon cooling, the system possesses ferromagnetism to antiferromagnetism transition at Néel temperature $T_N < T_C$.
Below $T_N $ sublattice A and B electrons give contribution to the magnetization. The transition is a partial ordered transition.
There is thermodynamic evidence for this transition in the magnetic specific heat of the system. As a function of temperature there are two maxima. At high temperature $T_C$ it is $λ$-type. At lower temperature $T_N$ it characterizes the transition from ferromagnetism to antiferromagnetism.
As an example of ferromagnetism to antiferromagnetism partial ordered transition we consider the material $La_{1-x}Ca_xMnO_3$ in the doping range $x\geq 0.50$.
Our calculations reproduce
the experimental magnetization-temperature curve. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_12671 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Antiferromagnetic to ferromagnetic phase transition as a transition to partial ordered spins. Application to $La_{1-x}Ca_xMnO_3$ in the doping range $x\geq 0.50$ Karchev, N. Strongly Correlated Electrons Magnetic state is a partial ordered state if only part of the electrons in the system give contribution to the magnetic order. We study Heisenberg model of two sublattice spin system, on the body-centered cubic lattice, with antiferromagnetic nearest neighbors exchange of sublattice A and B spins and two different ferromagnetic exchange constants for sublattice A ($J^A$) and B ($J^B$) spins. When $J^A>J^B$ the system undergoes transition from paramagnetism to ferromagnetism at Curie temperature $T_C$. Only the sublattice A spins give contribution to the magnetization of the system. Upon cooling, the system possesses ferromagnetism to antiferromagnetism transition at Néel temperature $T_N < T_C$. Below $T_N $ sublattice A and B electrons give contribution to the magnetization. The transition is a partial ordered transition. There is thermodynamic evidence for this transition in the magnetic specific heat of the system. As a function of temperature there are two maxima. At high temperature $T_C$ it is $λ$-type. At lower temperature $T_N$ it characterizes the transition from ferromagnetism to antiferromagnetism. As an example of ferromagnetism to antiferromagnetism partial ordered transition we consider the material $La_{1-x}Ca_xMnO_3$ in the doping range $x\geq 0.50$. Our calculations reproduce the experimental magnetization-temperature curve. |
| title | Antiferromagnetic to ferromagnetic phase transition as a transition to partial ordered spins. Application to $La_{1-x}Ca_xMnO_3$ in the doping range $x\geq 0.50$ |
| topic | Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2409.12671 |