Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physics
Positive Identification Of The Cr(4+)-->Cr(3+) Thermal Transition In Gaas, David C. Look, S. Chaudhuri, L. Eaves
Positive Identification Of The Cr(4+)-->Cr(3+) Thermal Transition In Gaas, David C. Look, S. Chaudhuri, L. Eaves
Physics Faculty Publications
Temperature-dependent Hall-effect measurements on two Cr-doped GaAs samples
show a dominant center at E1 =0.324—1.4 x 10-4T eV, with respect to the valence-band edge. By comparison with secondary-ion mass spectroscopy measurements of the Cr concentration, and recent EPR measurements of the Cr2+, Cr3+, and Cr4+ concentration in several samples, it is shown unambiguously that this energy describes the Cr4+→Cr3+ transition. This is the first conclusive evidence for a charge-state transition involving Cr4+ in GaAs.
Magneto-Hall And Magnetoresistance Coefficients In Semiconductors With Mixed Conductivity, David C. Look
Magneto-Hall And Magnetoresistance Coefficients In Semiconductors With Mixed Conductivity, David C. Look
Physics Faculty Publications
Magneto-Hall and magnetoresistance formulas, correct to order B2, are derived for the case in which both single-carrier and mixed-carrier effects are important. Also, a new magneto-Hall coefficient Is Presented: β=‹π4›‹π›/‹π2›3 - 1. Values of β for various scattering mechanisms are calculated and compared with experiment
Atomic Carbon In The Atmosphere Of Venus, Jane L. Fox
Atomic Carbon In The Atmosphere Of Venus, Jane L. Fox
Physics Faculty Publications
The densities of atomic carbon in the Venusian thermosphere are computed for a model which includes both chemistry and transport. The maximum density of C is 2.8×107 cm−3 near 150 km for an assumed O2 mixing ratio of 1×10−4. Photoionization of atomic carbon is found to be the major source of C+ above 200 km, and resonance scattering of sunlight by atomic carbon may be the major source of the C I emissions at 1561 Å, 1657 Å, and 1931 Å. The computed C+ densities are found to be in substantial agreement with …
A Stratospheric Chemical Instability, Jane L. Fox, Steven C. Wofsy, Michael B. Mcelroy, Michael J. Prather
A Stratospheric Chemical Instability, Jane L. Fox, Steven C. Wofsy, Michael B. Mcelroy, Michael J. Prather
Physics Faculty Publications
The equations which determine partitioning of Clx in steady state have multiple (three) solutions under conditions which might arise in the high-latitude winter stratosphere. Two of these solutions are stable, one is unstable, to infinitesimal perturbations. The relative stability of solutions is examined by subjecting the system to finite perturbations. The more stable solution is found to eliminate the less stable when semi-infinite volumes of the two solutions are placed in contact. The high-ClO, low-NO2 solution is more stable under most conditions. Transitions from less to more stable states are slow in winter but may occur more rapidly …