摘要:

The125Te Mo¨ssbauer data for crystalline and amorphous samples of As2Te3−xSex(x=0 to 2.9) are reported. The quadrupole splitting provides a useful probe for changes in the local environment about the tellurium with changes in phase and composition.

ISSN:0021-8979    

DOI:10.1063/1.325440

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Biaxially stretched PVF2films were poled by corona charging over a range of surface potentials not exceeding 10 kV. Studies of x‐ray diffraction patterns are presented together with the measured values of the piezoelectric constantd31of such films. The results indicate that the piezoelectricity in this polymer arises from the dipolar orientation of the polar crystallites.

ISSN:0021-8979    

DOI:10.1063/1.325441

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The pyroelectric effect in a thin film rigidly attached to a thick substrate is discussed and compared to the usual (stress‐free) effect. The effects of clamping are negligible for the geometry normally used in pyroelectric detectors in the case of three proper ferroelectric‐type pyroelectric materials of practical interest, namely, LiTaO3, Pb5Ge3O11, and Sr0.5Ba0.5Nb2O6. In the case of three wurzite‐type (nonferroelectric) pyroelectrics, namely, CdS, CdSe, and ZnO, the pyroelectric effect is drastically reduced by such clamping. Thus the pyroelectric effect in the latter materials appears to be piezoelectric in origin, in contrast to the case of most pyroelectric materials.

ISSN:0021-8979    

DOI:10.1063/1.325442

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Ionization rates in GaAs are determined from the measurement of photocarrier multiplication. Pure electron and hole initiations are achieved by using the novel crater mesa structure and appropriate optical‐injection wavelengths. The ionization rates for holes are greater than that for electrons except at highest fields. This agrees with the studies of Stillmanetal., except for the individual values. The ionization rates for electrons and holes are expressed as &agr;=5.6×106 exp(−2.41×106/E) and &bgr;=1.5×106 exp(−1.57×106/E), respectively.

ISSN:0021-8979    

DOI:10.1063/1.325443

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have studied the interaction of picosecond pulses from a Nd : glass laser with GaAs. The experimental data at incident powers up to ∼30 GW/cm2can be satisfactorily explained in terms of two‐photon absorption with &bgr;=0.015±0.005 cm/MW. The results are discussed in connection with the discrepancies existing in the literature about the experimental values of &bgr;. Their implications for the existence of self‐induced transparency effects in GaAs are also briefly pointed out.

ISSN:0021-8979    

DOI:10.1063/1.325444

出版商:AIP    

年代:1978

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.325445

出版商:AIP    

年代:1978

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.325446

出版商:AIP    

年代:1978

数据来源: AIP