Fast strain wave induced magnetization changes in long cobalt bars: Domain motion versus coherent rotation
نویسندگان
چکیده
Fast strain wave induced magnetization changes in long cobalt bars: Domain motion versus coherent rotation" (2015). A high frequency (88 MHz) traveling strain wave on a piezoelectric substrate is shown to change the magnetization direction in 40 lm wide Co bars with an aspect ratio of 10 3. The rapidly alternating strain wave rotates the magnetization away from the long axis into the short axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments were limited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the trav-eling strain wave does rotate the magnetization away from the long axis direction and both yield quantitatively similar values for the rotated magnetization. An investigation of the behavior of short axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation. Polarized neutron reflectivity data provide direct experimental evidence for this model. This is consistent with expectations that domain wall motion cannot track the rapidly varying strain.
منابع مشابه
Effects of bar length on switching field of nanoscale nickel and cobalt bars fabricated using lithography
The switching behavior of isolated nanoscale nickel and cobalt bars, which were fabricated using electron-beam lithography, was studied as a function of bar length. The bars have a 35 nm thickness, a 100 nm width, and a length varying from 200 nm to 5 mm. Magnetic force microscopy showed that except for the Ni bars with a length equal to or less than 250 nm, all other as-fabricated bars were si...
متن کاملNonmonotonic length dependence of switching field of nanolithographically
Previously, the switching field of nanolithographically defined single-domain permalloy and nickel bars was found to increase monotonically as the bar aspect ratio increases or as the bar width decreases. In this work, we will show, for the first time, that when the bar width is fixed, the switching field of nanolithographically defined single-domain nickel and cobalt bars changes nonmonotonica...
متن کاملEffect of bar width on magnetoresistance of nanoscale nickel and cobalt bars
The anisotropic magnetoresistance ~AMR! of nickel and cobalt bars of 1 mm length, 35 nm thickness, and width varying from 50 to 500 nm is studied. As the bar width is reduced from 500 to 50 nm, longitudinal MR change decreases from 0.8% to 0.2% and transverse MR change increases from 1.3% to 1.8% for the Ni bars; longitudinal MR change is zero and transverse MR change is constant at 1.6% for th...
متن کاملElectric field control of magnon-induced magnetization dynamics in multiferroics
We consider theoretically the effect of an inhomogeneous magnetoelectric coupling on the magnon-induced dynamics of a ferromagnet. The magnon-mediated magnetoelectric torque affects both the homogeneous magnetization and magnon-driven domain wall motion. In the domains, we predict a reorientation of the magnetization, controllable by the applied electric field, which is almost an order of magni...
متن کاملEffects of magnetostatic interaction between two single-domain cobalt bars on crystal anisotropy and switching field (abstract)
Understanding the magnetostatic field effects of a single-domain particle on its neighbors during thin film deposition and magnetic recording is essential to the development of magnetic recording media. Here, we present a unique study of such effects using nanofabrication technology and magnetic force microscopy ~MFM!. We fabricated pairs of single-domain cobalt bars. Each bar is 35 nm thick, 5...
متن کامل