Thin Metal Films with Dispersion-Hardening Magnetic Layers of Fe–Cr–Co Alloy

Abstract

Purpose. The study of the magnetic properties and surface state of permanent magnet fi lms,
not containing precious metals, on a silicon substrate with a magnetization vector in the plane
of the fi lm.
Methods and methodology. Permanent magnet fi lms are created by magnetron sputtering and
subsequent single-stage high-vacuum rapid annealing. The structure of these magnets contains
three layers: an adhesive layer of vanadium, a compensation layer of copper, and a ferromagnetic
layer of a dispersion-hardening alloy (LDHA) of the Fe-Cr-Co system. The properties of the fi lms
were studied using confocal microscopy, X-ray diffractometry. A magnetic hysteresis loop was
built using a vibromagnitometer and an assembly for the study of the magneto-optic Kerr effect.
The morphology of the surface was studied using an atomic force microscope and a scanning
electron microscope.
Results. After annealing, a signifi cant bending of the substrates occurred, and with an insuffi cient
thickness of the compensation layer, the destruction of both the fi lm and part of the silicon
substrate was observed. It was found that the increase in the coercive force of the fi lms correlated
with a high level of mechanical stresses in LDHA, characteristic for the decomposition of a
supersaturated solid solution of chromium in iron in bulk materials.
For the preservation of the permanent magnet fi lm, the thickness of the copper compensation
layer must be not less than that of LDHA.
Conclusions. For the fi rst time, a permanent magnet fi lm was obtained, based on a layer of
dispersion-hardening composition, not containing precious metals, with a level of coercive force
suffi cient for use in magnetoresistive integrated magnetic fi eld sensors.

REFERENCES
1. Masahiro Kitada, Yoshihisa Kamo, Hideo Tanabe. Magnetoresistive thin-fi lm sensor with permanent
magnet biasing fi lm. Journal of Applied Physics, 1985, v. 58(4), pp. 1667–1670. DOI: https://doi.org/10.1063/1.336058
2. Leo K. E. B. Serrona, Sugimura A., Fujisaki R., Okuda T., Adachi N., Ohsato H., Sakamoto I., Nakanishi
A. Magnetic and structural properties of NdFeB thin fi lm prepared by step annealing. Materials Science
and Engineering B, 2003, v. 97(1), pp. 59–63. DOI: https://doi.org/10.1016/s0921-5107(02)00401-4
3. Hlopov B. V., Samoylova V. S., Yuryev I. A. Changes of a condition of thin-fi lm layers of the magnetic
materials applied in systems of external memory of magnetic hard dick. T-Comm., 2015, v. 9(12),
pр. 5-11. (in Russ.)
4. Konoplev Yu. V., Izgorodin A. K. Structure formation, properties and application of hot-deformed alloys
UNDK and UNDCT. Available at: https://cyberleninka.ru/article/n/strukturoobrazovanie-svoystva-i-primenenie-goryachedeformirovannyh-splavov-yundk-iyundkt (accessed 24.10.2019)
5. Kaneko H., Homma M., Nakamura K. New ductile permanent magnet of Fe–Cr–Co system // AJP
Conference Proceedings. 1972, no. 5, рp. 1088–1092.
DOI: https://doi.org/10.1063/1.2953814
6. GOST 24897-81. Magnetic-hard deformable materials. Solid magnetik deformed materials. Marks. M.:
Publishing House of Standards, 1981, 21 p. (in Russ.)
7. Ovsyannikov G. A., Petrzhik A. M., Borisenko I. V., Klimov A. A., Ignatov Yu. A., Demidov V. V.,
Nikita S. A. Magnetic transport characteristics of strained La0.7Sr0.3MnO3 epitaxial manganite films.
J. Exp. Theor. Phys., 2009, v. 108(48), pp. 48-55. DOI: https://doi.org/10.1134/S1063776109010075
8. The website of the company “GEO-BAT”. Availablе at: https://www.geo-ndt.ru/pribor-6855-rentgenofl yorescentnii-analizator-metekspert.htm (accessed
24.10.2019)
9. Kekalo I. B., Samarin B. A. Physical metallurgy of precision alloys. Alloys with special magnetic properties.
Moscow, Metallurgy Publ., 1989, 496 p. (in Russ.)
10. Handbook of non-ferrous metals. Available at: https://libmetal.ru/index.htm (accessed 24.10.2019)
11. Handbook of non-ferrous metals. Available at: http://metal-archive.ru/vanadiy/955-ehanicheskiesvoystva-
vanadiya.html (accessed 24.10.2019)
12. Gromov D. G. Metallization of ultra-large integrated circuits. Tutorial / Eds: D. G. Gromov, A. I. Mochalov,
A. D. Sulimin, V. I. Shevyakov. M: BINOM, 2012, 277 p. (in Russ.)
13. Prokhorov I. A., Zakharov B. G. X-ray Diffraction Studies of Features of Relaxation and Distribution
of Macro-Stresses in Epitaxial Structures. J. Surf. Invest.: X-Ray, Synchrotron Neutron Tech., 1999. no. 2,
pp. 106–109. (in Russ.)
14. Stouney G. S. The Tension of Metallic Films Deposited by Electrolysis // Proceedings of the Royal
Society A: Mathematical, Physical and Engineering Sciences, 1909, v. 82(553), pp. 172–175. DOI: https://doi.org/10.1098/rspa.1909.0021
15. Dobrynin V. A. On the applicability of the stony formula for calculation of mechanical stresses in thick
fi lms and coatings. Technical Physics Letters, 1997, v. 23(18), pp. 32–3613. (in Russ.)
16. Gromov D. G. The dimensional effect of melting in fi lm structures of nanoelectronics. Nanotechnologies
in electronics. Issue 2: Sat. Tr. M.: Technosphere Publ., 2013, pp. 136–177. (in Russ.)
17. Gromov D. G., Gavrilov S. A., Redichev E. N., Ammov R. M. Kinetics of the melting-dispersion process
in copper thin fi lms. Phys. of the Solid State, 2007, v. 49(1), pp. 178–184. DOI: https://doi.org/10.1134/S1063783407010283