Magnetic relaxation dynamics driven by the first-order character of magnetocaloric La(Fe,Mn,Si)13
| Autor: | Milan Bratko, A. David Caplin, M. Katter, Luis Ghivelder, Edmund Lovell, Alexander Barcza, Lesley F. Cohen |
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| Rok vydání: | 2016 |
| Předmět: |
magnetocaloric effect
Phase transition Materials science General Science & Technology General Mathematics General Physics and Astronomy magnetic relaxation 02 engineering and technology magnetic refrigeration 01 natural sciences Paramagnetism Metastability MD Multidisciplinary 0103 physical sciences Magnetic refrigeration 010302 applied physics Condensed matter physics Transition temperature Relaxation (NMR) General Engineering Articles 021001 nanoscience & nanotechnology Magnetic hysteresis metamagnetic transition Ferromagnetism 0210 nano-technology |
| Zdroj: | Philosophical transactions. Series A, Mathematical, physical, and engineering sciences. 374(2074) |
| ISSN: | 1364-503X |
| Popis: | Here, we study the temporal evolution of the magnetic field-driven paramagnetic to ferromagnetic transition in the La(Fe,Mn,Si) 13 material family. Three compositions are chosen that show varying strengths of the first-order character of the transition, as determined by the relative magnitude of their magnetic hysteresis and temperature separation between the zero-field transition temperature T c and the temperature T crit , where the transition becomes continuous. Systematic variations in the fixed field, isothermal rate of relaxation are observed as a function of temperature and as a function of the degree of first-order character. The relaxation rate is reduced in more weakly first-order compositions and is also reduced as the temperature is increased towards T crit . At temperatures above T crit , the metastability of the transition vanishes along with its associated temporal dynamics. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’. |
| Databáze: | OpenAIRE |
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