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We present an experimental study of the dynamical screening effect of the built-in field in GaN-based quantum well structures by means of picosecond time-resolved luminescence measurements. Our results clearly show that the recombination dynamics of the ph ...
A strong de electric field dependence of the dielectric permittivity makes perovskite ferroelectrics promising materials for tunable microwave devices like phase shifters, tunable resonators, tunable filters etc. Dielectric loss is a crucial parameter for ...
Investigates the use of embedded optical fiber Bragg gratings to measure strain near a stress concentration within a solid structure. Due to the nature of a stress concentration (i.e., the strong nonuniformity of the strain field), the assumption that the ...
Pyrochlore free Pb(Mg1/3Nb2/3)O-3 (PMN) thin films were prepared from alkoxide-based solution precursors. The influence of different seeding layers and chemical solution on the microstructures is shown. Dielectric, electrostrictive, and piezoelectric prope ...
This article reviews recent advances in the studies of the piezoelectric properties of perovskite materials. Perovskite compositions are the best known and the largest family of ferroelectric and piezoelectric materials.: The dependence of the longitudinal ...
The longitudinal d(33) piezoelectric coefficient was studied in rhombohedral Pb(Zr0.6Ti0.4)O-3 thin films with (111), (100), and "random" orientation. The largest d(33) was found in (100)-oriented films and the smallest along the polarization direction in ...
The most important advances in the field of biomaterials over the past few years have been in bioactive biomaterials. Materials have been developed to incorporate bioactivity through biological recognition, including incorporation of adhesion factors, poly ...
This paper investigates the use of embedded optical fiber Bragg gratings to measure strain near a stress concentration within a solid structure. Due to the nature of a stress concentration (i.e. the strong non-uniformity of the strain field) the assumption ...
Electrostatic effects which take place in group-m nitrides in their wurtzite crystallographic phase have important consequences on the optical properties of (Al,Ga)N/GaN multiple quantum wells. A low-temperature photoluminescence study shows that the behav ...
The postresonator method proposed by Hakki and Coleman for the measurement of dielectric properties of solids in the microwave region is reexamined. Based on the experiments performed around 10 GHz, the limitations of the method in loss determination for m ...