Magnetization studies of binary and ternary Co-rich phases of the Co-Si-B system

Autor(es)

Bormio-Nunes, Cristina ^[1] ; Nunes, Carlos Angelo ^[1] ; Coelho, Adelino A. ^[2] ; Sodero Toledo Faria, Maria Ismenia ^[3] ; Suzuki, Paulo Atsushi ^[1] ; Coelho, Gilberto Carvalho ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, EEL, Dept Engn Mat DEMAR, BR-12600970 Sao Paulo - Brazil

^[2] Univ Estadual Campinas, Inst Fis, BR-13083970 Campinas, SP - Brazil

^[3] UniFoa Ctr Univ Volta Redonda, Nucleo Pesquisa, BR-27240560 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Alloys and Compounds; v. 508, n. 1, p. 5-8, OCT 15 2010.
• Citações Web of Science: 7

Resumo

CoB, CO(2)B, CoSi, Co(2)Si and CO(5)Si(2)B phases can be formed during heat-treatment of amorphous co-Si-B soft magnetic materials. Thus, it is important to determine their magnetic behavior as a function of applied field and temperature. In this study, polycrystalline single-phase samples of the above phases were produced via arc melting and heat-treatment under argon. The single-phase nature of the samples was confirmed via X-ray diffraction experiments. AC and DC magnetization measurements showed that Co(2)Si and CO(5)Si(2)B phases are paramagnetic. Minor amounts of either Co(2)Si or CoSi(2) in the CoSi-phase sample suggested a paramagnetic behavior of the CoSi-phase, however, it should be diamagnetic as shown in the literature. The diamagnetic behavior of the CoB phase was also confirmed. The paramagnetic behavior of CO(5)Si(2)B is for the first time reported. The magnetization results of the phase CO(2)B have a ferromagnetic signature already verified on previous NMR studies. A detailed set of magnetization measurements of this phase showed a change of the easy magnetization axis starting at 70K, with a temperature interval of about 13K at a very small field of 1 mT. As the strength of the field is increased the temperature interval is enlarged. The strength of field at which the magnetization saturates increases almost linearly as the temperature is increased above 70K. The room temperature total magnetostriction of the CO(2)B phase was determined to be 8 ppm at a field of 1T. (C) 2010 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/07463-8 - Estudo de propriedades magnetostrictivas de ligas Fe-M (M = Ga, Al) dopadas com boro
• Beneficiário: Cristina Bormio Nunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular