Solid State Physics Laboratory

About: Solid State Physics Laboratory is a facility organization based out in Delhi, India. It is known for research contribution in the topics: Quantum dot & Dielectric. The organization has 1754 authors who have published 2597 publications receiving 50601 citations.

Effect of Sintering Temperature on Structural and PiezoelectricProperties of PNN-PZT Ceramics

Abstract: Sintering temperatures affect the structural and piezoelectric properties of PbNi1/3Nb2/3-PbZrO3-PbTiO3 system considerably; therefore the effect has been studied on mechano-chemicallyprocessed powder. This process involves activating mixed oxides of PbO, NiO, Nb2O5, ZrO2 andTiO2, and in the present study, calcination steps at an intermediate temperatures were skippedwhich are usually required in conventional solid state reaction methods and chemical routes.Single-phase formation was confirmed from XRD patterns which shows rhombohedral structureat higher sintering temperature. Investigations of the microstructure indicate almost linear increasein grain size from 0.98 m to 2.56 m when the sintering temperature was varied from 1050 oC to1150 °C. A high value of planar coupling factor (kp) = 67 per cent and piezoelectric charge coefficient(d 33 ~ 750 pm/V; (as determined from strain versus electric field curve at low field) were obtainedfor the ceramic specimens sintered at 1100 °C. The maximum strain was observed ~ 0.21 per centat 40 kV/cm applied field for the sample sintered at 1100 °C for 4 h.

Electron g-factor anisotropy in an AlAs quantum well probed by ESR

Abstract: Electron spin resonance (ESR) was studied in an asymmetrically doped 16-nm AlAs quantum well grown in the [001] direction. Surprisingly the ESR was detectable even if the magnetic field was parallel to the surface of the two-dimensional system. This allowed us to investigate precisely the in-plane anisotropy of the electron $g$ factor. In the case of the magnetic field aligned along the [110] or $[1\overline{1}0]$ crystallographic axes only one ESR peak was observed, whereas it tended to split into two well-separated peaks when the in-plane component of the magnetic field was between these directions. This fact clearly indicates that two in-plane valleys at $X$ points of the Brillouin zone were occupied with electrons and each valley was characterized by the anisotropic $g$ factor with the [100], [010], and [001] principal axes. The principal $g$-factor values were extracted.

Theoretical model of the impedance of a fractal metal-electrolyte interface

Abstract: The impedance of a rough metal-electrolyte interface is known to show a complex impedance of type Z(ω) ∼ (iω)−gh at low frequencies. We study this problem for interfaces characterized by a self-similar fractal geometry. In contrast to previous theoretical studies we show that: (i) local field effects play an important role and have to be included explicitly in the model; (ii) power law behaviour is obtained for a broad range of parameters but other behaviours are also possible; (iii) the exponent η depends explicitly on various features of the model and not only on the fractal dimensions of the surface.