Title :
Magnetoresistance in magnetic tunnel junctions with amorphous electrodes
Author :
Nakajima, K. ; Fen, G. ; Coey, J.M.D.
Author_Institution :
Phys. Dept., Trinity Coll., Dublin, Ireland
Abstract :
Two different types of amorphous material, which includes CoFeB and Co2MnSi alloy were examined for use as electrodes in magnetic tunnel junctions (MTJ) to achieve a high tunnel magnetoresistance (TMR) ratio. Films were grown in a Shamrock tool by dc magnetron cosputtering from elemental targets on glass substrates or thermal-oxidized Si substrates. Film compositions were checked by energy dispersive X-ray analysis in a scanning electron microscope. Structural, and magnetic characterization was performed by X-ray diffraction and in a %T superconducting quantum interference device (SQUID) magnetometer, respectively. In the amorphous MTJs, the tunneling spin-polarization does not reflect the magnitude of the net magnetic moment directly.
Keywords :
X-ray chemical analysis; X-ray diffraction; amorphous magnetic materials; boron alloys; cobalt alloys; electrodes; electron spin polarisation; interface structure; iron alloys; magnetic moments; magnetic multilayers; magnetic thin films; manganese alloys; oxidation; scanning electron microscopy; silicon alloys; sputtered coatings; tunnelling magnetoresistance; SQUID magnetometer; Shamrock tool; Si substrates; Si-SiO2-Ta-Co2MnSi-AlOx-Co-IrMn-Ta; Si-SiO2-Ta-Co90Fe10Bx-AlOx-Co90Fe10Bx-IrMn-Ta; SiO; X-ray diffraction; amorphous electrodes; dc magnetron cosputtering; energy dispersive X-ray analysis; film composition; glass substrates; magnetic moment; magnetic tunnel junctions; scanning electron microscope; superconducting quantum interference device; thermal oxidation; tunnel magnetoresistance ratio; tunneling spin polarization; Amorphous magnetic materials; Amorphous materials; Electrodes; Magnetic films; Magnetic tunneling; SQUIDs; Substrates; Superconducting films; Superconducting magnets; Tunneling magnetoresistance;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1463667
