TY - JOUR
T1 - Discontinuity in heat capacity of Fe0.5Co0.5(110) alloy thin films
AU - Ramírez-Dámaso, G.
AU - Castillo-Alvarado, F. L.
AU - Cruz-Torres, A.
AU - Rójas-Hernández, E.
N1 - Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - In this work we calculate heat capacity of alloy thin films of FeCo on the surface of the plane (110), using three parameters, the concentration x(i), the lattice long range order parameter t(i) and the magnetic order parameter σ(i), being i the number of layers of the thin film. The formulations reported by Hill [1] in the context of small particles and Valenta's model [2] can be applied to the film structure when we treat a thin film as a system divided into subsystems equivalent to two-dimensional parallel layers. The FeCo bulk alloy is completely homogeneous while a thin film have spatial discontinuities in their surfaces. We consider three ferromagnetic thin films formed by 11, 15 and 19 layers in the Helmholtz's free energy, which is minimized applying their first partial derivatives with respect to chemical composition, long range order parameter and magnetic order parameter. We calculate internal energy and heat capacity as a function of temperature and we verify that have two jumps as are reported in literature for the bulk; there are many results of bulk or surface effects of FeCo, but no enough results about ferromagnetic FeCo thin films and this fact does this work interesting.
AB - In this work we calculate heat capacity of alloy thin films of FeCo on the surface of the plane (110), using three parameters, the concentration x(i), the lattice long range order parameter t(i) and the magnetic order parameter σ(i), being i the number of layers of the thin film. The formulations reported by Hill [1] in the context of small particles and Valenta's model [2] can be applied to the film structure when we treat a thin film as a system divided into subsystems equivalent to two-dimensional parallel layers. The FeCo bulk alloy is completely homogeneous while a thin film have spatial discontinuities in their surfaces. We consider three ferromagnetic thin films formed by 11, 15 and 19 layers in the Helmholtz's free energy, which is minimized applying their first partial derivatives with respect to chemical composition, long range order parameter and magnetic order parameter. We calculate internal energy and heat capacity as a function of temperature and we verify that have two jumps as are reported in literature for the bulk; there are many results of bulk or surface effects of FeCo, but no enough results about ferromagnetic FeCo thin films and this fact does this work interesting.
KW - A Alloys
KW - A Thin films
KW - C Heat capacity
KW - D Phase transitions
UR - http://www.scopus.com/inward/record.url?scp=84961907994&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2016.03.006
DO - 10.1016/j.jpcs.2016.03.006
M3 - Artículo
SN - 0022-3697
VL - 94
SP - 37
EP - 40
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
ER -