Relating microstructure to magnetocaloric properties in RE36Tb20Co20Al24 (RE = Gd, Dy or Ho) high-entropy metallic-glass microwires designed by binary eutectic clusters method. (20th June 2023)

• Record Type: Journal Article
• Authors: Yin, Hangboce; Wang, Jun-Qiang; Huang, Yongjiang; Shen, Hongxian; Guo, Shu; Fan, Hongbo; Huo, Juntao; Sun, Jianfei
• Is Part Of: Journal of materials science & technology. Volume 149(2023)
• Page Start: 167
• Page End: 176
• Publication Date: 2023-06-20
• Subjects: High-entropy metallic-glass -- Magnetocaloric effect -- High energy synchrotron X-ray diffraction -- Cryogenic temperature; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2022.12.008
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: The high-entropy metallic-glasses are designed by binary eutectic clusters method. The high-entropy metallic-glass microwires are prepared by melt-extraction method. High glass-forming ability of microwires is due to deep binary eutectic composition. The highest magnetic entropy change of the microwires is up to 10.3 J kg −1 K −1 (5 T). Magnetocaloric behavior of microwire is influenced by dispersion of local clusters. Abstract: The new high-entropy metallic-glasses (HE-MGs) are designed by using Dy and Ho to replace Gd in Gd36 Tb20 Co20 Al24 alloy based on the binary eutectic clusters method. Compared with the equiatomic Gd25 Tb25 Co25 Al25 HE-MG, the non-equiatomic RE36 Tb20 Co20 Al24 (RE = Gd, Dy, or Ho) alloys show better glass-forming ability, which is attributed to the deep binary eutectic compositions used for alloy design. All RE36 Tb20 Co20 Al24 alloys undergo second-order magnetic transition. An extreme peak value of magnetic entropy change is obtained as 10.3 J kg –1 K –1 (5 T) for the Ho36 Tb20 Co20 Al24 alloy. In - situ high-energy synchrotron X-ray diffraction was conducted to observe the microstructural difference among non-equiatomic samples at cryogenic temperatures. The results indicate that Gd36 Tb20 Co20 Al24 alloy possesses a relatively large average value of the dispersion of local clusters at a low-temperature range. This, combined with the critical exponent β close to 0.5 of Gd36 Tb20 Co20 Al24 alloy, leads to its widest working temperature span among non-equiatomic samples. This work successfully establishes the connection between microstructure and magnetocaloric properties of HE-MGs, which is beneficial for understanding the physical mechanism of the magnetocaloric behaviors of HE-MGs.