Yuri A. Kuzavko 3Dmitriy A. Kostiuk 3Michael M. Karpuk 1Vladimir G. Shavrov 2

1. Technical University of Koszalin, Raclawicka 15-17, Koszalin, Poland
2. Institute of Radio Engineering and Electronics RAS (IRE RAS), Mokhovaya, 11, Moscow 125009, Russian Federation
3. Brest State Technical University, Brest 224017, Belarus


Materials in which the reversible form and size control by magnetic field is possible, attracts much attention now. Highest effect is registered for Ni2+x+yMn1-xGay alloys. Crystal size there can be changed up to 6% by magnetic field (the theoretical deformation limit at transformation from austenite to martensite). With different stechiometric composition the temperature of martensite transition T may be close to the room one and lower than the Curie point of material. Sometimes martensite phase transition (PT) is preceded by premartensite one (PM PT) with anomalies of speed and absorption of longitudinal and transverse acoustic waves (LA and TA). The transverse mode TA2 is softened near the PM PT with the k = (ξ,ξ,0) wave vector at ξ =0.33 and e = (l 1 0) polarization vector. Its speed changes from 740 m/s (T=300 K) to 614 m/s (TPM=255 K) and 903 m/s (TM =215 K) at f=3.7 MHz frequency.

Acoustic anisotropy of a crystal reaches the value of A=28 at PM PT. Structural PT usually takes place in a Ni2MnGa crystal, and after that the orientational PT can be realized at temperature decrease and in H||[001] field.

We examined LA and TA inclined fall in (100) plane, reflection from the crystall free border (110) and from its border with liquid or dielectric. Spread directions and amplitudes of reflected waves in (001) plane of a crystal were determined, and are not pure modes but quasi-longitudinal and quasi-transverse. The colossal acoustic anisotropy of a crystal in its PT area brings allows to control the angles of reflection and transformation of wave types by temperature and magnetic field. Starting from a critical fall angle of TA, the LA, appeared at reflection, turns into the accompanying surface oscillation, and close to PT point it reflects into the volume.

Authors are grateful to BRFFI and RFFI (F04R-080, 04-02-81058, 03-02-17443 grants) and Ministry of Education of Belarus (05-550 grant) for their financial support of carried out research.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: must be provided.


Related papers
  1. Acousto-electronic Intellectual Sensors Based on Surface Waves
  2. The Influence of a Heysler Ferromagnetic Alloy Film on the Spread of Surface Acoustic Waves
  3. Amplification of evanescent acoustic waves by the layer of 2D magnetic composite
  4. The investigation of longitudinal acoustic waves in Heusler Ni53Mn25Ga22 alloy crystal with coupled magnetostructural transition
  5. The surface waves acoustoelectronic sensors based on films of Heusler alloy
  6. The acoustical spectral investigations of a ferromagnet Heusler Ni53Mn25Ga22 alloy crystal
  7. Surface waves in nanofilms of Heysler ferromagnetic alloy
  8. Magnetodeformations influence on spin-electron transport in nanofilms
  9. Acoustic Spectrum of Nanoparticles of a Heysler Shape Memory Ferromagnetic Alloy
  10. Photonic effect in ferromagnetic nano-films of Heysler alloy
  11. The acoustical investigations of a Ni53Mn25Ga22 Heysler alloy ferromagnet crystal
  13. Phase Transitions in Novel Ferromagnetic Shape Memory Alloys Ni-Mn-Sn
  14. Acoustical properties and acoustopseudoplastic effects in ferromagnetic shape memory alloy NiMnFeGa
  15. Martensitic transition in strong magnetic field and external stress in quaternary ferromagnetic shape memory alloy Ni-Mn-Fe-Ga
  16. Magnetocaloric effect in Ni2.19Mn0.81Ga Heusler alloy

Presentation: poster at E-MRS Fall Meeting 2005, Symposium C, by Yuri A. Kuzavko
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-07-11 19:23
Revised:   2009-06-07 00:44
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine