Multifunctional properties of Cr-substituted ferromagnetic Nd2Fe17. (October 2021)

• Record Type: Journal Article
• Authors: Datta, Subarna; Dan, Shovan; Gupta, Shuvankar; Chakraborty, Sudip; Mazumdar, Chandan
• Is Part Of: Intermetallics. Volume 137(2021)
• Publication Date: 2021-10
• Subjects: Intermetallic compounds -- Crystal structure -- X ray diffraction -- Thermal expansion -- Magnetic properties -- Magnetocaloric effect; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2021.107297
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: The detailed X-ray diffraction studies of the structural phase along with its thermal expansion properties have been carried out of the rare-earth based compounds Nd2 Fe17- x Cr x ( x = 0, 0.5, 1.0, and 2.0). They are crystallized in the rhombohedral structure (Th2 Zn17 type) with space group R-3m . A very negligible (close to zero) thermal expansion coefficient | α | = 1.9 × 10 −6 K −1, was found over a large temperature range 15–320 K in Nd2 Fe16.5 Cr0.5 compound ( T C ~ 366 K) attributable to the diminution of magneto-volume effect. This kind of zero thermal expansion (ZTE) magnetic system has a great practical significance having T C higher than 300 K. The parent compound Nd2 Fe17, as a magnetocaloric material, has high relative cooling power (RCP) (625 J kg −1 at μ 0 H = 0–9 T), elevated operational temperature (326 K) and comparatively high entropy change (|Δ S M | max ) at T C . Because of these properties Nd2 Fe17 can operate as a promising refrigerating system. The critical behaviour of all the four samples is studied by means of the isotherm magnetization in the vicinity of T C . The critical exponents are evaluated using various methods, for instance, modified Arrott plot, critical isotherm, Kouvel–Fisher plot in addition to the study of magnetocaloric effect. From the critical analysis it is revealed that all the four samples belong to different types of universal magnetic class. Highlights: Single component (Nd2 Fe16.5 Cr0.5 ) zero thermal expansion material with high T C. Nd2 Fe17, as a magnetocaloric material, possesses high relative cooling power. Nd2 Fe17 shows comparatively high.|ΔSM | max above room temperature (326 K). The characteristic of the phase transition is identified using critical analysis.