Determination of small magnitudes of magnetostriction in amorphous microwires with an arbitrary type of magnetic anisotropy

The magnetic anisotropy and magnetic structure of amorphous ferromagnets are largely determined by magnetoelastic interactions due to the absence of magnetocrystalline anisotropy, e.g., in amorphous microwires with a glass sheath, the source of anisotropy is the mechanical stresses that arise in the ferromagnetic core upon manufacturing. Hence, to control the magnetic structure and magnetization reversal processes occurred in amorphous magnetics, it is necessary to know the magnetostriction coefficient of the material. We propose an improved approach to measuring extremely small values of the magnetostriction coefficient of ferromagnetic microwires with an arbitrary type of magnetic anisotropy and magnetic microstructure. The samples of amorphous wires in a glass sheath made of Co₆₇Fe₅B₁₂Si₁₄Cr₃ alloys were studied. The type of magnetic anisotropy of the samples (from axial to circular) was changed using current annealing. The developed method is based on small-angle precession of magnetization around the wire axis, resulted from the effect of the axial magnetic field induced by an alternating current passed through the wire. A voltage signal generated in a detection coil wound around the sample at a frequency doubled with respect to the frequency of the alternating current was recorded using a lock-in amplifier. When exposed to external mechanical loads, the voltage signal changes, and an additional axial magnetic field (bias field) is required to maintain a constant level of this signal. The value of magnetostriction is determined from the dependence of the displacement field on mechanical loads. The maximum sensitivity of measurements in the range of 10^–8 – 10^–7 is achieved at a uniform magnetization, increased frequency of the alternating current, and high value of the ratio between the length and diameter of tested wire samples. The sign and magnitude of the magnetostriction constant change upon current annealing which correlates with modification of the magnetization curves. The results obtained can be used to determine and adjust the parameters of the actuators developed on the basis of the considered microwires (in particular, microsensors of mechanical stresses and microactuators).

1. Makhnovsky D. P., Panina L. V., Mapps D. J. Field-dependent surface impedance tensor in amorphous wires with helical and circumferential anisotropy / Phys. Rev. B. 2001. Vol. 63. P. 144424 – 144441. DOI: 10.1103/PhysRevB.63.144424

2. Pirota K., Kraus L., Chiriac H., Knobel M. Magnetic properties and GMI in a CoFeSiB glass-covered microwire / J. Magn. Magn. Mater. 2000. Vol. 221. P. L243 – L247. DOI: 10.1016/S0304-8853(00)00554-0

3. Zhukov A., Ipatov A., Churyukanova M., et al. Trends in optimization of giant magnetoimpedance effect in amorphous and nanocrystalline materials / J. Alloys and Compd. 2017. Vol. 727. P. 887 – 901. DOI: 10.1016/j.jallcom.2017.08.119

4. Zhukov A., Blanco J., Ipatov M., et al. Manipulation of domain wall dynamics in amorphous microwires through the magnetoelastic anisotropy / Nanoscale Research Letters. 2012. Vol. 7. 223. P. 1 – 8. DOI: 10.1186/1556-276X-7-223

5. Nematov M. G., Salem M. M., Adam A. M., Ahmad M., Yudanov N., Panina L. V., Morchenko A. T. Effect of Stress on Magnetic Properties of Annealed Glass-Coated Co71Fe5B11Si10Cr3 Amorphous Microwires / IEEE Trans. Magn. 2017. Vol. 53. P. 1 – 6. DOI: 10.1109/TMAG.2017.2702342

6. Sandacci S., Makhnovskiy D., Panina L., Larin V. Stress-Dependent Magnetoimpedance in Co-based Amorphous Wires and Application to Tunable Microwave Composites / IEEE Trans. Magn. 2005. Vol. 41. P. 3553 – 3555. DOI: 10.1109/TMAG.2005.854726

7. Torrejón J., Confalonieri G. Badini, Pirota K., Vázquez M. Multifunctional Magnetoelastic Sensor Device Based in Multilayer Magnetic Microwires / Sensor Letters. 2007. Vol. 5. P. 153 – 156. DOI: 10.1166/sl.2007.047

8. Hudak R., Varga R., Polacek I., et al. Addition of molybdenum into amorphous glass-coated microwires usable as temperature sensors in biomedical applications / Phys. Status Solidi A. 2016. Vol. 213. P. 377 – 383. DOI: 10.1002/pssa.201532574

9. Vazquez M., Gonzalez J., Hernando A. Induced magnetic anisotropy and change of the magnetostriction by current annealing in Co-based amorphous alloys / J. Magn. Magn. Mater. 1986. Vol. 53. P. 323 – 329. DOI: 10.1016/0304-8853(86)90177-0

10. Herzer G. Modern soft magnets: Amorphous and nanocrystalline materials / Acta Mater. 2013. Vol. 61. P. 718 – 734. DOI: 10.1016/j.actamat.2012.10.040

11. Morchenko A. T., Panina L. V., Larin V. S., et al. Structural and magnetic transformations in amorphous ferromagnetic microwires during thermomagnetic treatment under conditions of directional crystallization / J. Alloys Compd. 2017. Vol. 698. P. 685 – 691. DOI: 10.1016/j.jallcom.2016.12.247

12. Evstigneeva S. A., Morchenko A. T., Trukhanov A. V., et al. Structural and magnetic anisotropy of directionally-crystallized ferromagnetic microwires / EPJ Web of Conferences. 2018. Vol. 185. P. 1 – 4. DOI: 10.1051/epjconf/201818504022

13. Mitra A., Vazquez M. Measurement of the saturation magnetostriction constant of amorphous wire / J. Appl. Phys. 1990. Vol. 67. P. 4986 – 4988. DOI: 10.1063/1.344698

14. Zhukova V., Blanco J., Zhukov A., Gonzalez J. Studies of the magnetostriction of as-prepared and annealed glass-coated Co-rich amorphous microwires by SAMR method / J. Phys. D: Appl. Phys. 2001. Vol. 34. P. L113 – L116. DOI: 10.1088/0022-3727/34/22/101

15. Zhukova V., Corte-Leon P., Blanco J., et al. Electronic Surveillance and Security Applications of Magnetic Microwires (Review) / Chemosensors. 2021. Vol. 9. P. 1 – 22. DOI: 10.3390/chemosensors9050100

16. Panina L., Dzhumazoda A., Nematov M., Alam J., Trukhanov A., Yudanov N., Morchenko A., Rodionova V., Zhukov A. Soft Magnetic Amorphous Microwires for Stress and Temperature Sensory Applications / Sensors. 2019. Vol. 19. P. 1 – 24. DOI: 10.3390/s19235089

17. Larin V., Torcunov A., Zhukov A., et al. Preparation and properties of glass-coated microwires / J. Magn. Magn. Mater. 2002. Vol. 249. P. 39 – 45. DOI: 10.1016/S0304-8853(02)00501-2

18. Chiriac H. Preparation and characterization of glass covered magnetic wires / Mater. Sci. Eng. A. 2001. Vol. 304 – 306. P. 166 – 171. DOI: 10.1016/S0921-5093(00)01452-0

19. Gonzalez J., Blanco J., Hernando A., et al. Stress dependence of magnetostriction in amorphous ferromagnets: its variation with temperature and induced anisotropy / J. Magn. Magn. Mater. 1992. Vol. 114. P. 75 – 81. DOI: 10.1016/0304-8853(92)90334-K

20. Salem M., Nematov M., Uddin A., Panina L. V., Churyukanova M. N., Morchenko A. T. CoFe-microwires with stress-dependent magnetostriction as embedded sensing elements / IOP Conf. Series: J. Phys. Conf. Series. 2017. Vol. 903. P. 1 – 4. DOI: 10.1088/1742-6596/903/1/012007