The Wide Operating Temperature Range in the Magnetocaloric Composite Formed by RMn 2 Si 2 (R=Tm, Tb, and Dy) and HoCoSi
- PDF / 2,398,365 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 66 Downloads / 136 Views
ORIGINAL PAPER
The Wide Operating Temperature Range in the Magnetocaloric Composite Formed by RMn2Si2 (R=Tm, Tb, and Dy) and HoCoSi Compounds D. C. dos Reis 1 & J. K. P. França 1 & R. Andrade-Araujo 1 & A. O. dos Santos 1 & A. A. Coelho 2 & L. P. Cardoso 2 & L. M. da Silva 1 Received: 29 May 2020 / Accepted: 8 August 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract RMn2Si2 (R = Tm, Dy, and Tb) and HoCoSi alloys, presenting multiple magnetic phase transitions (except for TmMn2Si2 and HoCoSi) and large magnetocaloric effect (MCE), were physically mixed to produce a composite magnetic refrigerant. The used concentration of each alloy was 0.1(TmMn2Si2) + 0.35(DyMn2Si2) + 0.4(TbMn2Si2) + 0.15(HoCoSi). X-ray diffraction and magnetization measurements were used to investigate the crystallographic and magnetic properties of the samples. The results indicate the maximum values of magnetic entropy change (−ΔS max M ) of ~ 4.6 J/kg K under magnetic field change (ΔH) of 50 kOe. A large table-like MCE was observed for the composite sample. The full width at half maximum of ΔSM peak (δTFWHM) values reaches ~ 60.4 K (ΔH = 20 kOe) and ~ 67.2 K (ΔH = 50 kOe), which correspond to a respective ΔSM peak broadening of 230% and 180% for the composite sample compared with each compound studied individually. Such property is important for a material to operate in an ideal Ericsson cycle. Keywords Intermetallic compound . Composite sample . Magnetization . Table-like MCE
1 Introduction The RMX and RM2X2 (R = rare earth, M = transition metals, and X = p-block elements) families of compounds can present a variety of physical properties interesting for material science, due to their potential for technological applications [1–3]. The compounds of these families can crystalize in different structures: this fact favors the presence of versatile magnetic and electrical properties. It has been observed that the magnetic ordering temperatures in these compounds vary from very low (T < 2 K) to high temperatures (T > 300 K), depending on M and X elements. Some of these compounds have multiple magnetic phase transitions. Besides, large magnetocaloric effect and magnetoresistance were observed
* L. M. da Silva [email protected]; https://orcid.org/0000-0002-7233-0776 1
Centro de Ciências Sociais Saúde e Tecnologia (CCSST), Universidade Federal do Maranhão – UFMA R, Urbano Santos, s/n, Imperatriz, Maranhão 65900-410, Brazil
2
Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas – UNICAMP, R. Sérgio Buarque de Holanda, 777, Campinas, São Paulo 13083-859, Brazil
in many compounds of these families. Such characteristic enables these compounds to be good candidates for utilization in magnetic refrigeration. Solid-state magnetic refrigeration based on the magnetocaloric effect (MCE) is considered a promising technology because it is high-energy efficient and less polluting, compared with the conventional gas expansion and compression technology [4]. The MCE is an intrinsic phenomenon of magneti
Data Loading...
