Investigation of a novel material for magnetoelectronics: Co2Cr0.6Fe0.4Al

Heusler compounds are promising candidates for future spintronics device applications. The electronic and magnetic properties of Co2Cr0.6Fe0.4Al, an electron-doped derivative of Co2CrAl, are investigated using circularly polarized synchrotron radiation and photoemission electron microscopy (PEEM). Element specific imaging reveals needle shaped Cr rich phases in a homogeneous bulk of the Heusler compound. The ferromagnetic domain structure is investigated on an element-resolved basis using x-ray magnetic circular dichroism (XMCD) contrast in PEEM. The structure is characterized by micrometre-size domains with a superimposed fine ripple structure; the lateral resolution in these images is about 100 nm. The domains look identical for Co and Fe giving evidence of a ferromagnetic coupling of these elements. No ferromagnetic contrast is observed at the Cr line. Magnetic spectroscopy exploiting XMCD reveals that the lack of magnetic moment, detected in a SQUID magnetometer, is mainly due to the moment of the Cr atom.

[1]  C. Felser,et al.  Large negative magnetoresistance effects in Co2Cr0.6Fe0.4Al , 2003 .

[2]  C. Felser,et al.  Spin polarization of magnetoresistive materials by point contact spectroscopy , 2003 .

[3]  Ryota Goto,et al.  Large Tunneling Magnetoresistance at Room Temperature Using a Heusler Alloy with the B2 Structure , 2003 .

[4]  Gerhard Jakob,et al.  Element-specific magnetic moments from core-absorption magnetic circular dichroism of the doped Heusler alloy Co2Cr0.6Fe0.4Al , 2003 .

[5]  G. Schönhense,et al.  Investigating surface magnetism by means of photoexcitation electron emission microscopy , 2002 .

[6]  S. Imada,et al.  Orbital angular momentum and interpretation of core-absorption magnetic circular dichroism on the band picture in Co-based Heusler alloys Co2YSn (Y=Ti, Zr, and Nb) , 2002 .

[7]  M. Pileni,et al.  X-ray absorption spectra and X-ray magnetic circular dichroism studies at Fe and Co L2,3 edges of mixed cobalt-zinc ferrite nanoparticles : cationic repartition, magnetic structure and hysteresis cycles , 2001 .

[8]  Jonathan Z. Sun,et al.  Spin-polarized transport and magnetoresistance in magnetic oxides , 1999 .

[9]  J. V. Elp,et al.  Ligand field parameters obtained from and chemical shifts observed at the Cr L 2,3 edges , 1999 .

[10]  J. Moodera,et al.  Measuring the spin polarization of a metal with a superconducting point contact , 1998, Science.

[11]  J. Coey,et al.  Magnetoresistance of chromium dioxide powder compacts , 1998 .

[12]  G. Harp,et al.  ORIENTATION DEPENDENCE OF INTERLAYER COUPLING AND INTERLAYER MOMENTS IN FE/CR MULTILAYERS , 1997 .

[13]  Chen,et al.  Experimental confirmation of the X-ray magnetic circular dichroism sum rules for iron and cobalt. , 1995, Physical review letters.

[14]  K. Hono,et al.  Evolution of Nanoscale Ferromagnetic Particles in Co-Cr and Cr-Fe Alloys Observed by Atom Probe Field Ion Microscopy , 1995 .

[15]  K.H.J. Buschow,et al.  Magnetic and magneto-optical properties of heusler alloys based on aluminium and gallium , 1981 .