Počet záznamů: 1
Failure of the Maxwell relation for the quantification of caloric effects in ferroic materials
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SYSNO ASEP 0377247 Druh ASEP E - Elektronický dokument Zařazení RIV Záznam nebyl označen do RIV Název Failure of the Maxwell relation for the quantification of caloric effects in ferroic materials Tvůrce(i) Niemann, R. (DE)
Heczko, Oleg (FZU-D) RID, ORCID
Schultz, L. (DE)
Fähler, S. (DE)Vyd. údaje 2011 Jazyk dok. eng - angličtina Země vyd. DE - Německo Klíč. slova magnetocaloric effect ; martensitic transformation ; Ni-Mn-Ga ; entropy change Vědní obor RIV BM - Fyzika pevných látek a magnetismus CEP GAP107/11/0391 GA ČR - Grantová agentura ČR CEZ AV0Z10100520 - FZU-D (2005-2011) Anotace Giant caloric effects were reported in elasto-, electro- and magnetocaloric materials near phase transformations. Commonly, their entropy change is indirectly evaluated by a Maxwell relation. We report the fundamental failure of this approach. We analyze exemplarily the Ni-Mn-Ga magnetic shape memory alloy. An applied field results in magnetically induced reorientation of martensitic variants, which form during the phase transformation. This results in a spurious magnetocaloric effect, which only disappears when repeating the measurement a second time. This failure is universal as the vector character of the applied field is not considered in the common scalar evaluation of a Maxwell relation. Pracoviště Fyzikální ústav Kontakt Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579 Rok sběru 2013 Elektronická adresa http://arxiv.org/ftp/arxiv/papers/1110/1110.3617.pdf
Počet záznamů: 1