Title :
Mossbauer and X-ray study of (Fe1-xNix)7 Se8 and (Fe1-xCox)7Se 8
Author :
Kim, Eng Chan ; Yang, Jae Suk ; Kang, Sin Giu ; Lee, Dong Uk ; Nam, Hyo Duk
Author_Institution :
Dept. of Phys., Yeungnam Univ., Kyongsan, South Korea
fDate :
9/1/1996 12:00:00 AM
Abstract :
Mossbauer spectroscopy and X-ray diffraction. The crystal structure is found to be a triclinic superstructure of the NiAs structure while Fe7Se8 has a hexagonal structure. Changes of quadrupole shifts near 122 K for (Fe1-xNix )7Se8 and 124 K for (Fe1-xCox)7Se8 indicate that the spin-rotation transition proceeds abruptly, in contrast to the gradual transition reported for Fe7Se8 with a triclinic superstructure. Isomer shifts indicate a ferrous character for the iron ions at all four sites. The Neel temperature is found to decrease with increasing nickel and cobalt concentration
Keywords :
Mossbauer effect; Neel temperature; X-ray diffraction; cobalt compounds; crystal structure; ferromagnetic materials; iron compounds; isomer shift; nickel compounds; spin dynamics; stoichiometry; (Fe1-xCox)7Se8; (Fe1-xNix)7Se8; (FeCo)7Se8; (FeNi)7Se8; 122 K; 124 K; Mossbauer spectroscopy; Neel temperature; X-ray diffraction; crystal structure; ferrous behaviour; gradual transition; hexagonal structure; isomer shifts; quadrupole shift; spin-rotation transition; triclinic superstructure; Cobalt; Ferrimagnetic materials; Iron; Magnetic moments; Nickel; Physics; Silicon compounds; Spectroscopy; Temperature measurement; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
