Search for ferromagnetism in Hf2Co7: An investigation by perturbed angular correlation (PAC) spectroscopy

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:498

Article

Sewak, R.^1,2  Dey, C. C.^1,2 

[1] Saha Inst Nucl Phys, 1-AF Bidhannagar, Kolkata 700064, India

[2] Homi Bhabha Natl Inst, Mumbai 400094, Maharashtra, India

关键词: Intermetallics;    Mechanical alloying;    Hyperfine interactions;    Ferromagnetism;    Perturbed angular correlations;    PAC;    X-ray diffraction;   

DOI  :  10.1016/j.jmmm.2019.166105

来源: Elsevier

【 摘 要 】

Perturbed angular correlation (PAC) measurements in Hf2Co7 have been performed in the temperature range 77-973 K using the Hf-181 probe to observe ferromagnetism in this intermetallic alloy. From present measurements, no magnetic interaction is observed at any temperature in the above temperature range. Only two quadrupole interaction frequencies have been found. At room temperature, values of quadrupole frequency and asymmetry parameter are found to be omega(Q) = 15.7(4) Mrad/s, eta = 0, delta = 0 for site 1 (similar to 71%) and omega(Q) = 46(1) Mrad/s, eta = 0.74(5), delta = 5(3)% for site 2 (similar to 29%). Present results contradict with the earlier reported results where a room temperature ferromagnetism was found with a Curie temperature of similar to 400 K. X-ray diffraction measurement in Hf2Co7 has also been performed. From the measured XRD pattern, an almost pure phase of Hf2Co7 was observed.

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