W. G. Maisch

Bio: W. G. Maisch is an academic researcher from United States Naval Research Laboratory. The author has contributed to research in topics: Kerr effect & Magneto-optic Kerr effect. The author has an hindex of 3, co-authored 4 publications receiving 37 citations.

Magneto‐optical characterization of thin films of Fe1−xBx, Fe1−xSix and Fe‐overcoated permalloy

Abstract: The optical and magneto‐optical constants of several magnetically soft thin film alloys have been determined for λ=6328A using the transverse Kerr effect and ellipsometric techniques. The coercive force and magnetization were also measured. The alloy systems Fe1−xBx (0.15?x?0.5) and Fe1−xSix (0.1?x?0.3) and iron‐overcoated permalloys were studied as were Fe, Co and permalloy for reference. When used as transverse Kerr effect mirrors for ring laser gyros, the Fe‐rich Fe‐Si alloys and iron‐overcoated permalloys have the best calculated performance.

APPLICATIONS OF AMORPHOUS Fe-, CO-METALLOID AND RARE EARTH ALLOY THIN FILMS

Abstract: Amorphous thin films of transition metal (TM)-metalloid and TM-rare earth (R) alloys have been prepared by sputtering and multiple-target, electron-beam vapor deposition. Application of these has been made in several technically important areas including continuously variable surface acoustic wave (SAW) delay lines or resonators and magneto-optic mirrors for biasing ringlaser-gyroscopes (RLG). This paper deals with preparation, characterization, and tailoring of these alloy films to meet the required performance parameters for each application. In most instances the magnetically soft TM-metalloid films such as Fe-B, Fe-Si-B, and Fe-Cr-P-C show the best performance characteristics for SAW devices and magnetically switchable mirrors. The magnetically hard R-TM alloy films such as Tb-Fe and Tb-Co are excellent candidates for use as polar magnetooptic mirrors.

Hexagonal Ferrites from Melts and Aqueous Solutions, Magnetic Recording Materials

Abstract: Owing to their particular crystallographic properties, ferrimagnetic hexagonal ferrites exhibit a far greater coercive force than the conventional magnetic pigments. They therefore appear to be suitable for use in magnetic information storage procedures, some of which are novel and are at the development stage. Thus, magnetic tapes of high coercive force containing barium ferrite could be used as master tapes for copying magnetic information or for producing forgery-proof magnetic cards, if magnetic heads having high-order write fields were successfully developed. Moreover, platelet-like ferrite pigments in which the preferred direction of magnetic orientation is perpendicular to the plane of the platelet are of great interest for perpendicular magnetic recording. In this progress report, the crystal structures, magnetic characteristics of hexagonal ferrites, and chemical processes for their production are discussed. In particular, reactions in salt melts or under hydrothermal conditions produce finely divided pigments whose particles have a pronounced hexagonal, plate-like habit, a narrow particle size distribution, and advantageous magnetic properties. The magnetic properties of the pigments crystallized from salt melts may be adjusted by cation exchange.

Exploration of crystal structure, magnetic and dielectric properties of titanium-barium hexaferrites

Abstract: The BaFe12-xTixO19 hexaferrites up to x = 3.00 were extended. XRD patterns were Rietveld fitted for P63/mmc (no. 194) space group and the unit cell parameters were defined. The a parameter and V volume of unit cell change non-monotonically with × while the c parameter has linear behavior. The Ti4+ cations substitute the Fe3+ cations in the 2a, 4fVI and 12 k octahedral positions. This is confirmed by the Mossbauer spectroscopy. Ms spontaneous magnetization was determined with the law of approach to saturation from field magnetization at 5 K and 300 K. The e/ real part of the permittivity increases constantly with increasing temperature and decreases with frequency. The main objective of this study is an interpretation of the magnetic and dielectric properties of the titanium-barium hexaferrites which has performed in frame of breakdown of Fe3+ - O2– - Fe3+/2+(Ti4+) indirect superexchange interactions taking into account the positions occupation.

Magnetic and magneto‐optical properties of amorphous A1−xFex alloys (A = B, Ge, and Sn)

Abstract: Amorphous alloys of the type A1−xFex, where A represents B, Ge, or Sn, were prepared by two‐source coevaporation in the ranges 0.3⩽x⩽0.9, 0.30⩽x⩽0.65, and 0.45⩽x⩽0.64. The magneto‐optical properties of these alloys were examined by means of the polar Kerr effect. The magnetic properties of the alloys with B and Ge were also studied. The concentration dependence of the Fe moments in the Fe metalloid alloys is analyzed in terms of a model in which due account is taken of the fact that the variation of the heat of alloying in the various iron metalloid alloys entails a variable degree of intrinsic compositional short‐range order.

Applications of magneto-optics in ring laser gyroscopes

Abstract: Magneto-optical elements can be used to provide the frequency bias needed to prevent lock-in in ring laser gyroscopes by introducing a differential phase shift between counterpropagating beams. Some of the magneto-optical and magnetic requirements are noted and the various magneto-optical elements developed to satisfy these requirements are discussed. A number of magnetic metals and alloys as well as transparent magnetic garnets are described in terms of the properties needed to evaluate their magneto-optical performance. Fe, MnBi and garnets with high Faraday rotation appear to be the best candidates, and magneto-optic mirrors based on these have received industry attention. To reduce the optical loss to acceptable levels it is necessary to incorporate the magnetic metal mirrors into multilayer dielectric-magnetic thin film composites. A general scattering matrix method for handling multilayer composites which incorporate either an opaque or transparent magnetic film is described. It is based on the methods of Hunt. Typical results are shown for a number of Fe and garnet based multilayer mirrors.