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.

Correlation between amorphous and metastable crystalline alloys

Abstract: The local chemical environments and geometrical arrangement of atoms in metallic and covalent glasses [(Fe, Ni)3B, Zr3Fe, As2Te3] were studied by Mossbauer spectroscopy. It was found that in amorphous transition metal-metalloid and metal-metal alloys the chemical short-range order is similar to that of the (meta)-stable crystalline phases (Fe3B, Ni3B, Zr3Fe). The geometrical arrangement of near neighbours in amorphous As2Te3 is different from those present in the metastable (fcc) and stable (monoclinic) crystalline counterparts.

Dc resistivity of Mn-Ni-Zn ferrites

Abstract: DC resistivity of MnxNi0.5-xZn0.5Fe2O4 with compositions x=0.05 to 0.4 prepared by the citrate precursor method has been investigated. It has been observed that resistivity decreases with increase in Mn concentration. The observed temperature variation curves show two linear regions. Activation energy corresponding to both regions has been calculated. Possible conduction mechanisms contributing to the processes have been discussed. Variation of resistivity with sintering temperature establishes a correlation between microstructure and conductivity.

First-principle calculation of solar cell efficiency under incoherent illumination.

Abstract: Because of the temporal incoherence of sunlight, solar cells efficiency should depend on the degree of coherence of the incident light. However, numerical computation methods, which are used to optimize these devices, fundamentally consider fully coherent light. Hereafter, we show that the incoherent efficiency of solar cells can be easily analytically calculated. The incoherent efficiency is simply derived from the coherent one thanks to a convolution product with a function characterizing the incoherent light. Our approach is neither heuristic nor empiric but is deduced from first-principle, i.e. Maxwell’s equations. Usually, in order to reproduce the incoherent behavior, statistical methods requiring a high number of numerical simulations are used. With our method, such approaches are not required. Our results are compared with those from previous works and good agreement is found.

Dielectric spectroscopy of a high-polarization ferroelectric liquid crystal

Abstract: Dielectric spectroscopy investigations in the frequency range 50 Hz to 1 MHz have been carried out on a new ferroelectric liquid-crystalline material (S-(-)-4-(2-n-hexylpropionyloxy)biphenyl-4′-(3-methyl-4-decyloxy)benzoate) possessing a relatively large spontaneous polarization (P s ∼ 240 nC cm−2) and containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit. The effect of temperature on the dielectric relaxation modes has been investigated in the SmC* and N* phases. From dielectric dispersion data, relaxation frequency and dielectric strength of all detected relaxation modes have been evaluated and discussed. A new surface-like mode of relaxation frequency ∼11 kHz and dielectric strength 3.8, is seen to appear in the SmC* phase.