Resumo

ROSALES-RIVERA, Andrés. Static critical exponents, anisotropy, Hall and magneto-caloric effects, and magnetic interactions in FeCr, FeCo, and MnFe-based alloy ribbons. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2022, vol.46, n.180, pp.656-674.  Epub 18-Set-2023. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.1686.

This paper presents a comparative study of the critical exponents (ß, y, 5), the critical temperature Tc, the magnetic anisotropy, the Hall and magneto-caloric effects, and the magnetic interactions for the alloys [(Fe50Co50)75B20Si5]96Nb4, Fe65.5Cr8Cu1Nb3Si13.5B9, and Mn50Ni36Fe5Sn9 prepared by using melt-spinning. The above critical parameters and the magneto-caloric effect were determined from magnetization measurements. The values (β, δ, TC) for [(Fe50Co50)75B20Si5]96Nb4 and Fe65 5Cr8Cu1Nb3Si135B9 were (0.34 ± 0.09; 4.50 ± 0.45; 660 ± 30 K) and (0.52 ± 0.04; 3.62 ± 0.06; 481 ± 2 K), respectively, and for Mn50Ni36Fe5Sn9 it was (0.51 ± 0.03; 2.97 ± 0.03; 318 ± 8 K). The Hall resistivity vs. H curves exhibit an H S inflection field below which ordinary and extraordinary Hall effects are observed. Above H S , the ordinary Hall effect predominates and the extraordinary one is no longer seen. The H values for [(Fe Co) B Si ] Nb and Fe Cr Cu Nb Si B were 8 kOe and 4.42 kOe, respectively, and for Mn50Ni36Fe5Sn9, 1.84 kOe. The number of charge carriers, n c , was determined for H> H s , and its value for Fe65.5Cr8Cu1,Nb3,Si13.5 B9 and Mn50Ni36Fe5Sn9 was 2.71 x 1019 cm-3 and 129 x 1019 cm-3, respectively. The change in magnetic entropy and relative cooling capacity due to a field change of 10 kOe were evaluated and their maximum values close to T C for [(Fe50Co50)75B20Si5]96Nb4 and Fe65 5Cr8Cu1Nb3Si13.5B9 were (0.6; 0.75) Jkg-1K-1 and (57.4; 56.6) Jkg-1, respectively, and for Mn50Ni36Fe5Sn9, 0.5 Jkg-1K-1 and 25.1 Jkg-1, respectively. The possible effects of the exchange and spin-orbit interactions on the above results were also analyzed.

Palavras-chave : Universality classes; Static critical exponents; Hall and magneto-caloric effects; Magnetic alloys.

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