High TMR Ratio in ${\\rm Co}_{2}{\\rm FeSi}$ and ${\\rm Fe}_{2}{\\rm CoSi}$ Based Magnetic Tunn

Author

Sterwerf, C. ; Meinert, M. ; Schmalhorst, J.-M. ; Reiss, Guenter

Author_Institution

Dept. of Phys., Bielefeld Univ., Bielefeld, Germany

Volume

49

Issue

7

fYear

2013

fDate

Jul-13

Firstpage

4386

Lastpage

4389

Abstract

Magnetic tunnel junctions with Fe_1+zCo_2-xSi (0 ≤ x ≤ 1)electrodes and MgO barrier were prepared on MgO substrates by magnetron co-sputtering. Maximum tunnel magnetoresistance (TMR) ratios of 262% at 15 K and 159% at room temperature were observed for x = 0.75. Correlations of the annealing temperature dependent atomic ordering and TMR amplitude are discussed. The high TMR for an intermediate stoichiometry is ascribed to the adjustment of the Fermi energy within a minority spin pseudo gap.

Keywords

Fermi level; cobalt alloys; ferromagnetic materials; iron alloys; magnetic annealing; magnetic thin films; magnetic tunnelling; silicon alloys; sputter deposition; stoichiometry; tunnelling magnetoresistance; Fe_1+zCo_2-xSi; Fermi energy; MgO; MgO substrates; TMR; annealing; electrodes; magnetic tunnel junctions; magnetron cosputtering; minority spin pseudogap; stoichiometry; temperature 15 K; temperature 293 K to 298 K; tunnel magnetoresistance; Annealing; Compounds; Junctions; Magnetic tunneling; Metals; Temperature measurement; Tunneling magnetoresistance; Half-metals; Heusler compounds; TMR; X-ray diffraction; magnetic films; magnetoresistance; thin films;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2013.2238220

Filename

6559054

High TMR Ratio in and Based Magnetic Tunn

Sterwerf, C. ; Meinert, M. ; Schmalhorst, J.-M. ; Reiss, Guenter

jour

High TMR Ratio in ${\\rm Co}_{2}{\\rm FeSi}$ and ${\\rm Fe}_{2}{\\rm CoSi}$ Based Magnetic Tunn