Enhancement of magnetocaloric effect in the Gd₂Al phase by Co alloying

Journal Article · Fri Nov 14 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4900782· OSTI ID:1225530

Huang, Z. Y. ^[1]; Fu, H. ^[1]; Hadimani, R. L. ^[2]; Balfour, E. Agurgo ^[1]; Dembele, S. N. ^[1]; Teng, B. H. ^[1]; Jiles, D. C. ^[2]

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1. Univ. of Electronic Science and Technology of China, Chengdu (China)
2. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)

We observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and high level calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1225530
• Report Number(s): IS-J-8541; JAPIAU
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 18; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Gd2Al intermetallic compound
magnetocaloric effect
field-induced transition
aluminum
ferromagnetism
entropy
alloy phase transitions
Curie point