INTECIN   20395
INSTITUTO DE TECNOLOGIAS Y CIENCIAS DE LA INGENIERIA "HILARIO FERNANDEZ LONG"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Determination of Critical Exponents of Amorphous Magnetic FeCrCuNbSiB Alloy Ribbons
Autor/es:
A. ROSALES-RIVERA; J.C. HERNÁNDEZ-PARRA; A.A. VELÁSQUEZ-SALAZAR; D.F. GÓMEZ-MONTOYA; F. D. SACCONE
Lugar:
Cancún
Reunión:
Simposio; International Symposium on Metastable, Amorphous and Nanostructured Materials (ISMANAM 2014); 2014
Institución organizadora:
CONACyT
Resumen:
An understanding of effect of variation in the critical temperature on critical phenomena of heterogeneous magnets has been an outstanding problem in magnetic systems. On the other hand, amorphous magnetic ribbons of FeCuNbSiB have been of technological interest since their introduction in the ending of 1980s [1]. Over the years, these materials have also gained importance in condensed matter, where have provided an adequate scenario for experimental observation of several interesting physical phenomena including the giant magneto-impedance effect [2]. In this work we studied the critical behavior of the magnetization of FeCrCuNbSiB alloy system. These materials were prepared as amorphous alloy ribbons of Fe73.5-xCrxCu1Nb3Si13.5B9 with x = 0, 2, 4, 6, 8 and 10 (at.%) by means of the melt spinning technique. The temperature dependence of the magnetization of each sample was measured using a vibrating sample magnetometer (VSM-VersaLab by Quantum Design) at fixed external magnetic fields (H). H was applied along the longitudinal direction of the ribbons in the range 0.02 - 10 kOe. To extract the critical exponents and the Curie temperatures TC of the above materials we employ the method introduced in Ref.[3] which is based on linear superposition theory. This method considers the M(T) dependence as a distribution of power laws centered at defined critical temperatures TC. We have determined, for each value of x, the critical exponent Beta, for the spontaneous magnetization and the critical temperature TC. The Beta values found were 0.337 +/- 0.010, 0.336 +/- 0.008, 0.365 +/- 0.005, 0.391 +/- 0.005, 0,400 +/- 0.004 for x = 0, 2, 4, 6 and 8, respectively. For the sample x = 0 was not possible to determine a reliable Beta value. All measured samples show ferro-paramagnetic phase transition at high temperatures except the sample x = 10 which shows a possible super-paramagnetic behavior. References [1]Y. Yoshizawa, S. Oguma, and K. Yamauchi, J. Appl. Phys., Vol. 64, No. 10, 15 November 1988, 6044. [2]A. Rosales-Rivera, V.H. Valencia, P. Pineda-Gómez, Physica B 398 (2007) 252?255 [3]A. Berger, G. Campillo, P. Vivas, J.E. Pearson, S.D. Bader, E. Baca, P. Prieto, J. Appl. Phys. 91, 8393 (2002)