Showing papers by "Thomas J. Silva published in 1997"
TL;DR: In this paper, the non-reciprocal nature of the magneto-optic Kerr effect (MOKE) was exploited to distinguish polarization rotation due to sample magnetization from other spurious sources, such as sample roughness and birefringence of the microscope optics.
Abstract: We describe an optical detection scheme for scanning Kerr-effect microscopy (SKEM) which does not require modification of the magnetic state of a sample for domain observation. The scheme exploits the nonreciprocal nature of the magneto-optic Kerr effect (MOKE) to distinguish polarization rotation due to sample magnetization from other spurious sources, such as sample roughness and birefringence of the microscope optics. We present SKEM images of domain structures in lithographically patterned Ni81Fe19 elements which demonstrate the imaging capabilities of the new detection scheme for materials with typical MOKE magnitudes.
21 citations
TL;DR: In this paper, the second-harmonic magneto-optic Kerr effect investigations of magnetic heterostructures were performed and it was shown that the addition of 2 nm Co layer between Cu and Ni81Fe19 increases the magnetic signature in the secondharmonic intensity by more than a factor of two.
Abstract: We report second-harmonic magneto-optic Kerr effect investigations of magnetic heterostructures. The heterostructures studied are multilayers of Si/Al2O3/Cu(50 nm)/Ni81Fe19(x), Si/Al2O3/Cu(50 nm)/Co(2 nm)/Ni81Fe19(x), and Si/Al2O3Cu(50 nm)/Ni81Fe19(x)/Cu(5 nm), where x ranges from 1 to 30 nm. For films thinner than the optical penetration depth, the transverse second-harmonic Kerr effect experimentally separates and distinctly identifies each of these multilayered structures. We find that the addition of the 2 nm Co layer between Cu and Ni81Fe19 increases the magnetic signature in the second-harmonic intensity by more than a factor of two. This increase correlates with the observed magnetoresistance increase in spin valves with the addition of Co. For films thicker than the penetration depth, the structures with air-exposed Ni81Fe19 are identical, but they differ significantly from Ni81Fe19 films capped with Cu. We used spectroscopic ellipsometry to determine the linear optical properties of each film in ...
9 citations
01 Apr 1997
TL;DR: In this article, the second-harmonic magneto-optic Kerr effect and the magnetoresistance of patterned Ta/Ni/sub 81/Fe/sub 19/Ta spin-valve test structures were simultaneously measured.
Abstract: We have simultaneously measured the second-harmonic magneto-optic Kerr effect and the magnetoresistance of patterned Ta/Ni/sub 81/Fe/sub 19//Cu/Ni/sub 81/Fe/sub 19//Ta spin-valve test structures. For fields applied parallel to the bias-current direction, we observed a one-to-one correlation between the magnetoresistance and the magnetization-dependent second-harmonic intensity. The dependence of the second-harmonic intensity on magnetic field indicates that the detected second-harmonic response arises largely from the top Ni/sub 81/Fe/sub 19//Ta interface. The existence of this one-to-one correlation implies that the second harmonic depends linearly on magnetization, thus offering a method for interface-specific magnetometry.
3 citations