Search

Your search keyword '"Wigen, P. E."' showing total 316 results
Start Over Author "Wigen, P. E."
316 results on '"Wigen, P. E."'

112. Structural properties of TmFeO3 in the spontaneous reorientation region.

Author

Tsymbal, L. T., Kamenev, V. I., Khara, D. A., Bazaliy, Ya. B., and Wigen, P. E.

Subjects
LOW temperatures, ORTHOFERRITES, CRYSTALLOGRAPHY, ANTIFERROMAGNETISM, RARE earth metal compounds
Abstract

X-ray studies of TmFeO3 single crystals in the spontaneous spin-reorientation region demonstrate the absence of lattice distortions and no lowering of the symmetry of the crystal from rhombic to monoclinic and thus confirm the purely magnetic nature of the Γ2–Γ24–Γ4 spin reorientation in orthoferrites. [ABSTRACT FROM AUTHOR]

Published
2006
Full Text
View/download PDF

119. Magnetic structure in FeCo–Al<INF>2</INF>O<INF>3</INF> granular films studied by the ferromagnetic resonance

Author

Lesnik, N. A., Gontarz, R., Kakazei, G. N., Kravets, A. F., Wigen, P. E., and Dubowik, J.

Abstract

The effect of oblique co-deposition on magnetic properties of cermet films is studied on a series of (Fe50Co50)x–(Al2O3)1–x granular films with nominal FeCo content x varied at 0.07 &lt; x &lt; 0.49, using FMR. Three observed signals are attributed to local regions differing of compositions, each varying from the nominal x. A microstructure-induced oblique anisotropy has been found above percolation. Its origin may be due to some elongation of grains along a growth direction tilted from the film normal.

Published
2003
Full Text
View/download PDF

123. Magnetic Hysteresis in ErFeO[sub3] Near the Low Temperature Erbium Ordering Transition.

Author

Tsymbal, L. T., Bazaliy, Ya. B., Kakazei, G. N., Palomares, F. J., and Wigen, P. E.

Subjects
HYSTERESIS, MATERIALS at low temperatures, ERBIUM, IRON oxides, MAGNETIZATION, HYSTERESIS loop
Abstract

Magnetic hysteresis of ErFeO[sub3] is investigated in the temperature interval between the compensation point T[subcomp] = 46K and erbium ordering transition at T[sub12] = 4.1 K. The shape of the hysteresis loops evolves from rectangular near the compensation point to a double-triangle loops (similar to perminvar loops) near the erbium ordering transition. The evolution of the loop shape explains the peculiar temperature hysteresis observed at constant applied field. [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
View/download PDF

127. Transient space charge limited current spectroscopy method of measuring the position and concentration of trap levels in semi-insulating materials.

Author

Yuan, S. H., Pardavi-Horvath, M., and Wigen, P. E.

Subjects
INSULATING materials, TESTING
Abstract

A new method is reported to measure the position and concentration of trap levels in semi-insulating materials where the regular deep level transient spectroscopy method is not applicable. In the proposed method, a transient space charge limited current (TSCLC) associated with the trap levels is measured using a capacitance balanced square wave voltage source, a voltage limiter-amplifier and a double box car averager. The TSCLC method is demonstrated on a p-type Y2.01Ca0.99Ge0.91Fe4.09O12 magnetic garnet sample ρ300=107 Ω cm. The trap level is located at 0.36 eV above the valence band edge and the concentration of the trapped holes is found to be 1013–1015 cm-3. [ABSTRACT FROM AUTHOR]

Published
1988
Full Text
View/download PDF

130. SHEAR AND LONGITUDINAL MAGNETOELASTIC WAVES IN TRANSVERSELY MAGNETIZED RODS

Author

LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF LOCKHEED PALO ALTO RESEARCH LAB, Comstock,R. L., Wigen,P. E., LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF LOCKHEED PALO ALTO RESEARCH LAB, Comstock,R. L., and Wigen,P. E.

Abstract

An analysis is presented of the propagation of magnetoelastic waves in transversely magnetized rods. Efficiencies for longitudinal wave-spin wave and shear wave-spin wave conversion are evaluated for the case of a (110) rod magnetized along (111). Alongitudinal to shear wave converter in yttrium iron garnet is discussed which is estimated to have 20-dB conversion efficiency at 3 Gc/sec. (Author), Pub. in Journal of Applied Physics v36 n8 p2426-8 Aug 1965 (Copies not available to DDC or Clearinghouse customers).

Published
1964

131. EVIDENCE OF UNPINNED SURFACE SPINS FROM PARALLEL SPIN-WAVE RESONANCES IN PERMALLOY FILMS

Author

LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF, Wigen,P. E., Kooi,C. F., Shanabarger,M. R., LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF, Wigen,P. E., Kooi,C. F., and Shanabarger,M. R.

Abstract

The nature of the surface-spin boundary condition and of the parallel resonances for spin-wave resonance in Permalloy films is determined. Computer solutions of the classical equation of motion of the spins, using the inhomogeneous internal field model, are compared with experimental results. The mode positions and intensities as a function of frequency, film thickness, and internal effective field variation are calculated. This results in the conclusion that the surface spins are unpinned and that the inhomogeneous internal field model is valid for the parallel case as well as for the perpendicular case. The frequency dependence of the intensity of the parallel modes is particularly strong evidence for this conclusion. It is also shown that the mode positions for the perpendicular case are unlikely to reliably determine the surface-spin boundary condition. (Author), Pub. in Journal of Applied Physics (U. S.) v35 n11 p3302-11 Nov 1964 (Copies not available to DDC or Clearinghouse customers).

Published
1964

Catalog

Books, media, physical & digital resources
See catalog results