Various concentrations of PbF2-doped BaF2 crystals were grown by the Bridgman method using a shaped graphite heater. The room temperature optical absorption spectra showed two UV bands (labeled A and D), characteristic Pb2+ ions. structure was analyzed Gaussian multi-peak fitting. distribution ions along effective segregation coefficient studied method. obtained >1. not uniformly distributed...

A nondestructive approach is described that applicable for studying the In-segregation phenomena in ultra-thin In(Ga)As/GaAs nanostructures grown by molecular beam epitaxy. The proposed method utilizes only experimental photoluminescence (PL) spectroscopy data and effective bandgap simulation of specially designed nanostructures. On example InAs In0.25Ga0.75As quantum wells with thicknesses 1 m...

Cement substitution in self compacting concrete (SCC) is emphasized to conserve environment, reduce cost and utilize waste materials. This paper focuses on comparing the permeability and drying shrinkage of SCC containing Wollastonite micro fiber (WMF), a cheap pozzolanic fiber with respect to flyash. Microsilica was added for providing required viscosity to maintain homogeneity of the mixes. T...

The social geography of cities is argued to be changing globally; rising economic inequality associated with increasing segregation. Yet, income has been predominantly mobilised through national and regional imaginaries. In cities, a number factors such as the normative policy motivation intervene in “disadvantaged” neighbourhoods, have led (concentrations of) poverty becoming prioritised empir...

In this paper we present results of a study on the yttrium doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. Results of trace analysis on raw materials and crystals are presented. The segregation coefficient of yttrium ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, dec...

The distribution in a niixed crystal A1-,B,C grown from an either (A, B)-rich or C-rich solution zone (e.g. travelling heater method or related techniques) is to be described by PFANN’S zone melting function which depends on the segregation coefficient and a characteristic length. Using pseudobinary mole fractions x the characteristic length of the distribution function is not the actual length...

In this paper, we present results of a study on Sb doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. The segregation coefficient of Sb ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, decay kinetics and radiation damage were measured. It is found that Sb doping alone is ...

Vertical shaking of a mixture of small and large beads can lead to segregation where the large beads either accumulate at the top of the sample, the so-called Brazil nut effect (BNE), or at the bottom, the reverse Brazil nut effect (RBNE). Here we demonstrate experimentally a sharp transition from the RBNE to the BNE when the particle coefficient of friction increases due to aging of the partic...