Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries
In this review, we outline some principal theoretical knowledge of the properties of frustrated spin systems and magnetic thin films. The two points we would like to emphasize: (i) the physics in low dimensions where exact solutions can be obtained; (ii) the physics at phase boundaries where interes...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-02-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/21/2/175 |
| _version_ | 1798042113992032256 |
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| author | Hung T. Diep |
| author_facet | Hung T. Diep |
| author_sort | Hung T. Diep |
| collection | DOAJ |
| description | In this review, we outline some principal theoretical knowledge of the properties of frustrated spin systems and magnetic thin films. The two points we would like to emphasize: (i) the physics in low dimensions where exact solutions can be obtained; (ii) the physics at phase boundaries where interesting phenomena can occur due to competing interactions of the two phases around the boundary. This competition causes a frustration. We will concentrate our attention on magnetic thin films and phenomena occurring near the boundary of two phases of different symmetries. Two-dimensional (2D) systems are in fact the limiting case of thin films with a monolayer. Naturally, we will treat this case at the beginning. We begin by defining the frustration and giving examples of frustrated 2D Ising systems that we can exactly solve by transforming them into vertex models. We will show that these simple systems already contain most of the striking features of frustrated systems such as the high degeneracy of the ground state (GS), many phases in the GS phase diagram in the space of interaction parameters, the reentrance occurring near the boundaries of these phases, the disorder lines in the paramagnetic phase, and the partial disorder coexisting with the order at equilibrium. Thin films are then presented with different aspects: surface elementary excitations (surface spin waves), surface phase transition, and criticality. Several examples are shown and discussed. New results on skyrmions in thin films and superlattices are also displayed. By the examples presented in this review we show that the frustration when combined with the surface effect in low dimensions gives rise to striking phenomena observed in particular near the phase boundaries. |
| first_indexed | 2024-04-11T22:31:01Z |
| format | Article |
| id | doaj.art-44979af0b0bb463f8b35325848b9e80f |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-04-11T22:31:01Z |
| publishDate | 2019-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-44979af0b0bb463f8b35325848b9e80f2022-12-22T03:59:24ZengMDPI AGEntropy1099-43002019-02-0121217510.3390/e21020175e21020175Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase BoundariesHung T. Diep0Laboratoire de Physique Théorique et Modélisation, Université de Cergy-Pontoise, CNRS, UMR 80892, Avenue Adolphe Chauvin, CEDEX, 95302 Cergy-Pontoise, FranceIn this review, we outline some principal theoretical knowledge of the properties of frustrated spin systems and magnetic thin films. The two points we would like to emphasize: (i) the physics in low dimensions where exact solutions can be obtained; (ii) the physics at phase boundaries where interesting phenomena can occur due to competing interactions of the two phases around the boundary. This competition causes a frustration. We will concentrate our attention on magnetic thin films and phenomena occurring near the boundary of two phases of different symmetries. Two-dimensional (2D) systems are in fact the limiting case of thin films with a monolayer. Naturally, we will treat this case at the beginning. We begin by defining the frustration and giving examples of frustrated 2D Ising systems that we can exactly solve by transforming them into vertex models. We will show that these simple systems already contain most of the striking features of frustrated systems such as the high degeneracy of the ground state (GS), many phases in the GS phase diagram in the space of interaction parameters, the reentrance occurring near the boundaries of these phases, the disorder lines in the paramagnetic phase, and the partial disorder coexisting with the order at equilibrium. Thin films are then presented with different aspects: surface elementary excitations (surface spin waves), surface phase transition, and criticality. Several examples are shown and discussed. New results on skyrmions in thin films and superlattices are also displayed. By the examples presented in this review we show that the frustration when combined with the surface effect in low dimensions gives rise to striking phenomena observed in particular near the phase boundaries.https://www.mdpi.com/1099-4300/21/2/175frustrationphase transitionreentrancedisorder linessurface spin wavesmagnetic thin filmstheorysimulation |
| spellingShingle | Hung T. Diep Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries Entropy frustration phase transition reentrance disorder lines surface spin waves magnetic thin films theory simulation |
| title | Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries |
| title_full | Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries |
| title_fullStr | Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries |
| title_full_unstemmed | Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries |
| title_short | Phase Transition in Frustrated Magnetic Thin Film—Physics at Phase Boundaries |
| title_sort | phase transition in frustrated magnetic thin film physics at phase boundaries |
| topic | frustration phase transition reentrance disorder lines surface spin waves magnetic thin films theory simulation |
| url | https://www.mdpi.com/1099-4300/21/2/175 |
| work_keys_str_mv | AT hungtdiep phasetransitioninfrustratedmagneticthinfilmphysicsatphaseboundaries |