Neutron diffraction and reflectivity studies of the Cr Néel transition in Fe/Cr (001) superlattices

✍ Scribed by Eric E. Fullerton; S. Adenwalla; G.P. Felcher; K.T. Riggs; C.H. Sowers; S.D. Bader; J.L. Robertson

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 561 KB
• Volume: 221
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00951-5

✦ Synopsis

The effects on the interlayer coupling of the Cr N6el transition is studied in Fe/Cr(00 1) superlattices. The N6el transition is suppressed for Cr layer thickness < 42 A. For > 42 A of Cr, the N6el temperature TN initially increases rapidly and then asymptotically approaches its bulk value with a three-dimensional transition-temperature shift exponent value of)~ = 1.4 _+ 0.3. Neutron diffraction confirms both the Cr antiferromagnetic order and the existence of the incommensurate, transverse spin density wave whose nesting wave vector is the same as that of bulk Cr. The ordering of the Cr dramatically alters the coupling of the Fe layers. The biquadratic Fe interlayer coupling observed for T > TN vanishes below TN as confirmed by polarized neutron reflectivity. The behavior can be understood in terms of finite-size and spin frustration effects at rough Fe Cr interfaces.