Magnetic phase diagram of the Gd-Al and Gd-Cu amorphous alloy systems

Journal Article · Wed Mar 01 04:00:00 EST 1978 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.324889· OSTI ID:5051274

McGuire, T R; Mizoguchi, T; Gambino, R J; Kirkpatrick, S

Amorphous films of Gd/sub x/Al/sub 1-x/ and Gd/sub y/Cu/sub 1-y/ where x and y vary from approx.0.2 to 0.8 have been prepared by sputtering. Magnetization measurements in fields from 0.1 to 18 000 Oe over the temperature range 4.2 to 300 /sup 0/K allowed us to determine the magnetic phase diagram for these systems. Spin glass and ferromagnetic states as well as intermediate regions have been identified. For all compositions the paramagnetic Curie temperature is positive having values from 18 to 150 /sup 0/K. When x < or =0.40, Gd/sub x/Al/sub 1-x/ displays a susceptibility cusp and relaxation effect characteristic of a spin glass. For compositions x=0.56 and 0.81 a peak in the low field susceptibility is found which is 30 /sup 0/K below the ferromagnetic Curie temperature as estimated by an Arrott plot. Since magnetic saturation at 4.2 /sup 0/K is not reached for these two alloys, we assign them to an intermediate state. The Gd/sub y/Cu/sub 1-y/ system also has spin glass like behavior at y=0.21 and y=0.31 but at higher concentrations only easily saturated ferromagnetism is found. Since anisotropy energies are usually small in Gd compounds, observations of a spin glass phase must reflect the presecnce of a wide variation of exchange interactions.

• Research Organization: IBM Research Center, Yorktown Heights, New York 10598
• OSTI ID: 5051274
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 49:3; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals &amp; Alloys-- Physical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
AMORPHOUS STATE
ANISOTROPY
BINARY ALLOY SYSTEMS
COPPER ALLOYS
CURIE POINT
EXCHANGE INTERACTIONS
FERROMAGNETISM
FILMS
GADOLINIUM ALLOYS
INTERACTIONS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
MAGNETIZATION
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
SPIN GLASS STATE
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE