abstract
In this report, a successful thermodynamical model was employed to understand the structural transition in Er5Si4, able to explain the decoupling of the magnetic and structural transition. This was achieved by DFT calculations, which were used to determine the energy differences at 0K, using a LSDA+U approximation. It was found that the M structure is the stable phase at low temperatures, as verified experimentally with a value of Delta F-0=-0.262eV. Finally, a variation of Seebeck coefficient (similar to 6 mu V) was determined at the structural transition, which allows to conclude that the electronic entropy variation is negligible in the transition. (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
keywords
MAGNETIC REFRIGERATION
subject category
Physics
authors
Costa, RM; Belo, JH; Barbosa, MB; Algarabel, PA; Magen, C; Morellon, L; Ibarra, MR; Goncalves, JN; Fortunato, NM; Amaral, JS; Araujo, JP; Pereira, AM
our authors
João Cunha de Sequeira Amaral
Assistant Researcher
João Nuno Santos Gonçalves
Junior Researcher
João Silva
Post-Doc Fellowship
Nuno Fortunato
Research FellowshipGroups
G2 - Photonic, Electronic and Magnetic Materials
G6 - Virtual Materials and Artificial Intelligence
acknowledgements
This work was partially supported by the projects FEDER/POCTI n0155/94, PTDC/CTM/NAN/5414/2014 from Fundacao para a Ciencia e Tecnologia (FCT), Portugal. The authors thank the Portuguese Foundation for Science and Technology (FCT) for grants SFRH/BD/88440/2012 (JHB) and SFRH/BD/97591/2013 (MSB), SFRH/BD/97591/2013 (MBB), SFRH/BPD/82059/2011 (JNG), IF/01089/2015 (JSA). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. C.M. acknowledges the support of the Fundacion ARAID. This work was supported by the Spanish Ministry of Science (through Project Nos. MAT2014-51982-C2-R and C1-R, including FEDER funding) and the Aragon Regional government (Project No. E26).