Heteroepitaxial Growth of 4^′-Nitorobenzylidene-3-Acetamino-4-Methoxyaniline on the Single Crystal of 4^′-Nitrobenzyliden-3-Ethylcarbonylamino-4-Methoxyaniline

Abstract

Relativistic distorted-wave (RDW) calculations are carried out for the electron impact excitation of the lowest autoionizing states np 5 (n + 1)s 2 , 2 P 3/2,1/2 in Na(n = 2), K(n = 3), Rb(n = 4) and Cs(n = 5) alkali atoms from the ground np 6 (n + 1)s, 2 S 1/2 state. Detailed results in the range of near threshold to 1.5 keV incident electron energies are obtained for total cross sections of the magnetic substates of the individual 2 P 3/2 and 2 P 1/2 states. Utilizing these, the results are presented for their total cross sections, alignment parameter A 20 of the 2 P 3/2 state and the intensity of the ejected electrons from the 2 P 3/2 state. RDW calculations excluding the exchange effect and relativistic Born approximation calculations are also performed for comparison. The results are compared and discussed in the light of earlier available results and the recently reported experimental data from the Freiburg group (Germany). S Kaur and R SrivastavaRb(n = 4) and Cs(n = 5). The interest in the study of such states started with some preliminary calculations to estimate their expected significant contribution to the electron impact ionization process as predicted experimentally (see Aleksakhin 1969, Nygaard 1975). An account of the work done so far on this subject has been given by Pangantiwar and Srivastava (1987). Further details can be obtained from the two recent experimental papers from the Freiburg group, Germany (see Matterstock et al 1995, Feuerstein et al 1998. Their measurements are, in fact, the first reliable data on the study of electron impact excitation of the lowest autoionizing levels in K and Na atoms which can be compared directly with the available theoretical cross section results. In their paper they presented, along with a critical discussion, the comparison of their data with the available earlier theoretical calculations and stressed that a further reliable theoretical probe of the problem is desirable. In the light of their comments we re-examine this problem and report our theoretical calculation.In order to understand the excitation of the lowest autoionizing levels in the alkalis and their alignment, we consider the following two processes, i.e. electron impact direct ionization and ionization through the excitation autoionization of these levels:

Nonlinear optical effect of organic crystal heterostructures of benzylidene-aniline derivatives by two-step molecular-beam heteroepitaxy

“…8 We also have reported that the two-step procedure using the MNBA-Et homoepitaxial layer ͑homoepi-layer͒ in organic molecular-beam epitaxy ͑OMBE͒ 9 is an effective method of fabricating a transparent MNBA heteroepitaxial layer ͑heteroepi-layer͒ with higher crystal quality. 10,11 We have tried to apply this OMBE technique to the fabrication of an electro-optic ͑EO͒ waveguide device and proved that MNBA/MNBA-Et heterostructure works as an EO device. Moreover, we have found that the EO coefficient of the MNBA heteroepi-layer depends on the thickness of the MNBA-Et homoepi-layer.…”