Diffusion Layer Ultrasonic Transducer

Abstract

By diffusing copper into the surface of conductive cadmium sulfide single-crystal samples, thin piezo-electrically active layers have been formed. Such diffusion layers have been shown to act as ultrasonic transducers with operating frequencies well above 100 Mc. Short delay lines with less than 30 dB of insertion loss at 175 Mc have been made using such diffusion layer transducers.

Thermodynamics of electromechanically coupled mixed ionic-electronic conductors: Deformation potential, Vegard strains, and flexoelectric effect

“…However, the situation can differ significantly for the case of materials with finite electronic conductivity, in which both concentration fields and electrostatic field are nonuniform within the material. Electrostatic fields in the material give rise to strains due to electrostriction [32,33,34,35] and space-charge [36] effects. Secondly, the changes in the redox state of Jahn-Teller (JT) active cations can give rise to additional strain coupling mechanisms through the deformation potential [37,38,39,40,41,42].…”

“…Electrostatic fields in the material give rise to strains due to electrostriction [32,33,34,35] and space-charge [36] effects. Secondly, the changes in the redox state of Jahn-Teller (JT) active cations can give rise to additional strain coupling mechanisms through the deformation potential [37,38,39,40,41,42].…”

Nonlinear screening, and spin and cyclotron gaps in the 2D electron gas of GaAs/AlGaAs heterojunctions

“…If a radiofrequency signal is applied to a :ow-resistivity sample of CdS containing a compensated diffusion layer, most of the field falls across this thin high-resistance region. A diffusionlayer ultrasonic transducer is thus formed (Foster 1963), which behaves in a manner completely analagous to a quartz-plate transducer and propagates ultrasonic waves into the bulk of the crystal. From measurements of the fundamental ultrasonic frequency of the transducer and a knowledge of the velocity of sound in the diffusion direction, the layer thickness is calculated.…”

Excitation of atomic force microscope cantilever vibrations by a Schottky barrier

“…15͒ or CdS. 16 Later, volume and surface acoustic-wave generating devices using depletion zones in nonpiezoelectric semiconductors were proposed. [17][18][19][20] Mechanical stress is created if an external electrical field is applied to depletion layers in p-n junctions or Schottky contacts.…”