Magnetic anisotropy, coupling and transport in epitaxial Co/Cr superlattices on MgO (100) and (110) substrates

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:465232

Picconatto, J J; Pechan, M J ^[1]; Fullerton, E E ^[2]

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1. Miami Univ., Oxford, OH (United States). Dept. of Physics
2. Argonne National Lab., IL (United States). Materials Science Div.

Superlattices of Co/Cr have been epitaxially sputtered onto MgO (100) and (110) substrates coated with Cr(100) and (211) buffer layers. The Co thickness is fixed at 20{angstrom} and the Cr thickness varied from 7 to 22{Angstrom}. On the MgO(110)/Cr(211) substrates, coherent hcp-Co(1{bar 1}00)/bcc-Cr(211) superlattice structures are formed. On MgO(100)/Cr(100), XRD suggest strained hcp-Co(11{bar 2})/bcc-Cr(100) superlattices. Magnetization measurements show fourfold magnetic in- plane anisotropy for the MgO(100) orientation and twofold for the MgO(110). By utilizing a simple model based on perpendicular uniaxial anisotropies, we have concluded that the fourfold anisotropy has its origin in the second-order uniaxial Co anisotropy energy. The antiferromagnetic interlayer coupling strength exhibits a maximum value of 0.15 erg/cm{sup 2} at a Cr thickness of 13{angstrom} in the MgO(110) orientation. The MgO(100) orientation exhibits its strongest coupling of 0.55 erg/cm{sup 3} at 10{angstrom} Cr thickness. Modest GMR values no larger than 3% are observed and we find no evidence of enhanced AMR effects recently reported for Co(1{bar 1}00)/Cr(211) superlattices.

• Research Organization: Argonne National Lab., IL (United States). Materials Science Div.; Miami Univ., Oxford, OH (United States). Dept. of Physics
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: FG02-86ER45281; W-31109-ENG-38
• OSTI ID: 465232
• Report Number(s): ANL/MSD/CP--91154; CONF-961141--12; ON: DE97003884
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM
COBALT
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETIC STORAGE DEVICES
MAGNETORESISTANCE
SUPERLATTICES