Curie temperatures of amorphous RFe/sub 2/ alloys

Conference · Thu Jan 01 04:00:00 EST 1976 · AIP (Am. Inst. Phys.) Conf. Proc.; (United States)

OSTI ID:7359091

Rhyne, J J

Curie temperatures of the series of amorphous rare earth-iron alloys RFe/sub 2/ (where R = Gd, Tb, Dy, Ho, Er, and Y) have been determined from Belov-Goryaga plots of the magnetization isotherms. The Curie temperature of GdFe/sub 2/ is 500/sup 0/K, and drops sharply (e.g. ErFe/sub 2/ T/sub c/ = 105/sup 0/K) as one proceeds to the right in the above series (decreasing R spin). The observed Curie temperatures exhibit a smooth variation with the DeGennes factor of the rare earth ion, with the zero spin limit YFe/sub 2/ exhibiting no long-range order. This is in marked contrast to the analogous crystalline Laves phase compounds for which YFe/sub 2/ has a 535/sup 0/K Curie temperature and which show a much weaker dependence on the rare earth spin. These results imply a more significant effect of the structural disorder on the direct Fe--Fe exchange versus the RKKY Fe--R and R--R couplings. A molecular field model describing these interactions has been used to calculate the expected Curie temperature for both the amorphous and crystalline series. Overall agreement with the observed T/sub c/'s was less satisfactory for the amorphous than for the crystalline materials.

• Research Organization: National Bureau of Standards, Washington, DC
• OSTI ID: 7359091
• Conference Information: Journal Name: AIP (Am. Inst. Phys.) Conf. Proc.; (United States) Journal Volume: 29
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
AMORPHOUS STATE
CURIE POINT
DYSPROSIUM ALLOYS
ERBIUM ALLOYS
GADOLINIUM ALLOYS
HOLMIUM ALLOYS
INTERMETALLIC COMPOUNDS
IRON ALLOYS
MAGNETIZATION
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
TERBIUM ALLOYS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
YTTRIUM ALLOYS