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Abstract |
Nonlinear Magneto-Acoustic Phenomena
Near Spin-Reorientation Instability
V.Preobrazhensky (Wave Research Center
of Prokhorov General Physics Institute RAS and Institut d'Electronique et de
Micro-Electronique du Nord (IEMN-DOAE-UMR CNRS 8520)-Ecole Centrale de Lille,
Lille, France); P.Pernod (Institut d'Electronique et de Micro-Electronique du
Nord (IEMN-DOAE-UMR CNRS 8520), Ecole Centrale de Lille, Villeneuve d'Ascq,
France)
e-mail:
preobr@newmail.ru
Magneto-elastic
interaction increases dramatically acoustic nonlinearity of solids near spin
reorientation instability [1]. Manifestations of giant effective anharmonisity
of magnetic crystals such as: dynamic elasticity control, elastic mode
conversion, instability of collective oscillation type, multiple bistability,
quasi-periodic transitions in nonlinear acoustic excitations are demonstrated
in the present paper [2]. Rare earth thin films with giant magnetostriction are
of interest for actuation of modern micro-electro-mechanical systems. The
results of studies of nonlinear dynamic properties of rare earth mulilayered
nanostructures N*(TbFe/Fe) are presented. Magneto-elastic anomalies near spin
reorientation transition are found experimentally and described theoretically
[3]. The strongly nonlinear phenomena of quasi-static switch of deformation and
sub-harmonic excitations of elastic modes are considered. Magnetic control of
elasticity in solids is an advantageous principle of stimulated parametric emission
of phase conjugate ultrasound waves [4]. The problem of output power [5] and
bandwidth of magneto-acoustic phase conjugator is discussed. 1. V.I.Ozhogin,
V.L.Preobrazhensky. Journ. Magn. & Magn. Materials.100,544( 1991). 2. P.Pernod, V.Preobrazhensky. Journ. Appl.
Phys. 81.5709(1997) ; Journ. Magn. & Magn. Mater. 184. 173(1998); 185.
127(1998). 3. N.Tiercelin, V.Preobrazhensky, P.Pernod, H.Le Gall, J.Ben
Youssef. Journ. Magn.&Magn.Materials. 210. 302(2000). 4. A.P.Brysev,
L.M.Krutyansky, V.L.Preobrazhensky. Uspekhi Phys. Nauk.. 168. 877 (1998). 5.
V.Preobrazhenskii. Acoust.Physics..46. 746(2000).
Section
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