Magneto x-ray study of a gadolinium-iron amorphous alloy

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5385781

Keller, E N

This work reports the measurement of the magnetic x-ray absorption of an amorphous Gd-Fe ferrimagnetic thin film. The Gd to Fe concentration in the sample was 1:4. The magnetic x-ray effect is the x-ray analog of magneto-optic absorption effects. Magneto x-ray effects arise when a solid has different indices of refraction for right and left circularly polarized x-rays. The difference in absorption of left and right circularly polarized x-rays is called the magneto x-ray absorption. This absorption is proportional to the net spin of the final state density of states. At the L3 edge, the main x-ray transition is from initial Gd(2p) core states to final Gd(5d) unoccupied states. Since the 5d states have a net spin polarization in ferromagnetic Gd, this experiment hoped to directly observe how that polarization changes for Gd in the alloy. The magneto x-ray absorption at the Gd L3 edge will be proportional to the sign and amount of the net spin polarization of the 5d electrons. The magnetic x-ray absorption coefficient was found to be at least 0.0005 smaller than the linear absorption coefficient at the Gd white line energy. This was measured for the amorphous alloy at room temperature. Lock-in techniques were used to obtain the small limit to the absorption. A simple model for the size of the magnetic x-ray absorption coefficient in Gd suggests that the Gd(5d) net spin polarization is less than 0.01 Bohr magnetons per atom.

• Research Organization: Washington Univ., Seattle (USA)
• OSTI ID: 5385781
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GADOLINIUM ALLOYS
MAGNETO-OPTICAL EFFECTS
X-RAY DIFFRACTION
IRON
AMORPHOUS STATE
FERRIMAGNETIC MATERIALS
THIN FILMS
ALLOYS
COHERENT SCATTERING
DIFFRACTION
ELEMENTS
FILMS
MAGNETIC MATERIALS
MATERIALS
METALS
RARE EARTH ALLOYS
SCATTERING
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties