The whole list of physics

Abstract:: Some mistakes present in the paper written by Isenberg I.et al.are pointed out,and two new methods for deriving the Hall effect formula are offered.
Key words:: Hall effect;Laplace equation; boundary conditions; end effects

Abstract:: The paper presents the study of a single layer of chiral plate microwave absorber. The dependence of the microwave reflectance on the frequency for a single layer of the chiral plate microwave absorber is reported. The results indicate that the chiral microwave absorber gets a good performance. It means that the chiral material is a good microwave absorbing material. In addition, the phenomenon of the polarization plane rotation is observed as the electromagnetic wave passes through the chiral sample.
Key words:: chiral material; absorbing material; absorber

(R.D. 1995-03-31 P.D. 1995-09-20 Vol.31 No.5 pp.561-570)

[back] [Return to Physics(1995)]

Abstract:: Giant Faraday rotation as a function of photon energy and composition for Cd_1-xMn_xTe and Cd_1-xFe_xTe in temperature range 70 K to 300 K has been measured by using extinction, alternating magnetic field and magneto-optical modulation methods. Faraday rotation angles are negative and a single-oscillator model fit the data very well for Cd_1-xMn_xTe with relatively high compositions (x 0.1). It is shown that Cd_1-xFe_xTe crystals exhibit the same order giant Faraday rotation cha- racteristic as Cd_1-xMn_xTe. With relatively low composition x, Faraday rotation angles vary from positive to negative when photon energy close to the band gap edge, a multioscillator model has been successfully used to explain the data. Alternating magnetic field method is found to be the best one in this region, however, magneto-optical modulation method takes advantages of its high accurate for thin samples or under low magnetic field.
Key Words:: diluted magnetic semiconductors; faraday effect; magneto- optical-modulation.

(R. D. 1994-09-07 P. D. 1995-09-20 Vol. 31 No. 5 pp. 571-579)

[back] [Return to Physics(1995)]

Abstract:: Absorption and Magnetic Circular Dichroism(MCD) spectra have been measured in a new diluted magnetic semiconductor Zn_1-xCo_xS (with x=0.001, 0.01, 0.03, 0.048, 0.053 and 0.063) at temperature 73K to 300K in visible and near infrared region respectively for the first time. A series of absorption and MCD spectra have been observed. Both of the spectra are in good agreement and the peaks are independent on the composition of sample and corresponding to the transitions between the different energy levels of Co²⁺ ion in a crystal field of Td symmetry.
Key words:: diluted magnetic semiconductor; absorption spectra; magnetic circular dichroism spectra

(R. D. 1994-11-03 P. D. 1995-09-20 Vol. 31 No. 5 pp. 580-585)

[back] [Return to Physics(1995)]

Abstract:: Spectra of the new type diluted magnetic semiconductors Zn_1-xCo_xSe and Zn_1-xCo_xS related to transitions between the dif- ferent energy level of Co²⁺ ions for states of d⁷ configuration have been calculated by crystal field theory. The comparison of calculated and observed spectra of Co²⁺ ions have been given. Both are in good agreement in the low energy level part. Crystal field D_q, Racah B, C and spin-orbit coupling parameters have been obtained and observed spectra of Co²⁺in Zn_1-xCo_xSe and Zn_1-xCo_xS have been designeted, respectively.
Key words:: diluted magnetic semiconductors; crystal field; spin- orbit coupling.

(R.D. 1995-03-11 P.D. 1995-09-20 Vol.31 No.5 pp.586-590)

[back] [Return to Physics(1995)]