Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7988093 | Solid State Communications | 2017 | 5 Pages |
Abstract
We report a theoretical study of the magnetocaloric effect of Terbium (Tb) thin films due to finite size and surface effects in the helimagnetic phase, corresponding to a temperature range from TC=219Â K to TN=231Â K, for external fields of the order of kOe. For a Tb thin film of 6 monolayers submitted to an applied field (ÎH=30Â kOe, ÎH=50Â kOe and ÎH = 70Â kOe) we report a significative change in adiabatic temperature, ÎT/ÎH, near the Néel temperature, of the order ten times higher than that observed for Tb bulk. On the other hand, for small values of the magnetic field, large thickness effects are found. For external field strength around few kOe, we have found that the thermal caloric efficiency increases remarkably for ultrathin films. For an ultrathin film with 6 monolayers, we have found ÎT/ÎH = 43Â K/T while for thicker films, with 20 monolayers, ÎT/ÎH = 22Â K/T. Our results suggest that thin films of Tb are a promising material for magnetocaloric effect devices for applications at intermediate temperatures.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
V.D. Mello, D.H.A.L. Anselmo, M.S. Vasconcelos, N.S. Almeida,