Growth of detector-grade CZT by Traveling Heater Method (THM): An advancement

In this present work we report the growth of Cd{sub 0.9}Zn{sub 0.1}Te doped with In by a modified THM technique. It has been demonstrated that by controlling the microscopically flat growth interface, the size distribution and concentration can be drastically reduced in the as-grown ingots. This results in as-grown detector-grade CZT by the THM technique. The three-dimensional size distribution and concentrations of Te inclusions/precipitations were studied. The size distributions of the Te precipitations/inclusions were observed to be below the 10-{micro}m range with the total concentration less than 10{sup 5} cm{sup -3}. The relatively low value of Te inclusions/precipitations results in excellent charge transport properties of our as-grown samples. The ({mu}{tau}){sub e} values for different as-grown samples varied between 6-20 x 10{sup -3} cm{sup 2}/V. The as-grown samples also showed fairly good detector response with resolution of {approx}1.5%, 2.7% and about 3.8% at 662 keV for quasi-hemispherical geometry for detector volumes of 0.18 cm{sup 3}, 1 cm{sup 3} and 4.2 cm{sup 3}, respectively

Spectroscopic investigation and continuous-wave laser demonstration utilising single crystal cr2+:CdZnTe

We report spectroscopic and laser investigations of a novel mid-infrared laser material Cr2+:Cd1-xZnxTe, x=0.04. The threshold for continuous-wave laser action was 55 mW of absorbed power and up to 3 mW output was obtained

Head-on collision of ion acoustic solitary waves in an electron-positron-ion plasma with superthermal electrons

The head-on collision of ion acoustic solitary waves in a three-component unmagnetized plasma with cold ions, Boltzmann distributed positrons, and superthermal electrons is investigated using the extended Poincare-Lighthill-Kuo method. The effects of the ratio of electron temperature to positron temperature, the spectral index, kappa, of the electron kappa distribution, and fractional concentration of positron component (p) on the phase shift are studied. It is found that the presence of superthermal electrons play a significant role on the collision of ion acoustic solitary waves. (C) 2010 American Institute of Physics.[doi:10.1063/1.3528544

Head-on collision of ion acoustic solitary waves in an electron-positron-ion plasma with superthermal electrons

The head-on collision of ion acoustic solitary waves in a three-component unmagnetized plasma with cold ions, Boltzmann distributed positrons, and superthermal electrons is investigated using the extended Poincare-Lighthill-Kuo method. The effects of the ratio of electron temperature to positron temperature, the spectral index, kappa, of the electron kappa distribution, and fractional concentration of positron component (p) on the phase shift are studied. It is found that the presence of superthermal electrons play a significant role on the collision of ion acoustic solitary waves. (C) 2010 American Institute of Physics.[doi:10.1063/1.3528544

Magnetic and electrical properties of single-phase multiferroic BiFeO\u3csub\u3e3\u3c/sub\u3e

We have reported the structural, thermal, microscopic, magnetization, polarization, and dielectric properties of BiFeO3 ceramics synthesized by a rapid liquid-phase sintering technique. Optimum conditions for the synthesis of single-phase BiFeO3 ceramics were obtained. Temperature-dependent magnetization and hysteresis loops indicate antiferromagnetic behavior in BiFeO3 at room temperature. Although saturated ferroelectric hysteresis loops were observed in single-phase BiFeO3 ceramic synthesized at 880 °C, the reduced polarization is found to be due to the high loss and low dielectric permittivity of the ceramic, which is caused by higher leakage current

Magnetic and spectroscopic characteristics of ZnMnO system

We report on the observation of room-temperature ferromagnetism in epitaxial (Zn,Mn)O films grown by a pulsed-laser deposition technique using high-density targets. The X-ray, microscopic, spectroscopic and magnetic properties of target material containing 6 at.% of Mn and films were compared. The target shows the presence of large clusters exhibiting paramagnetic behavior. However, ferromagnetic properties were observed in (Zn,Mn)O films grown at a substrate temperature of 500 °C and with an oxygen partial pressure of 1 mTorr. Although, crystalline quality of the film improves with increasing substrate temperature, the ferromagnetism becomes weaker

Semiconductor disk laser pumped cr2+:chalcogenide lasers

The optically-pumped semiconductor disk laser is shown to be a practical low-noise pump source for Cr2+:chalcogenide lasers. Results on cw-pumping of a Cr2+:ZnSe and quasi-cw-pumping of a Cr2+:CdZnTe laser are presented

High-temperature ferromagnetism in pulsed-laser deposited epitaxial (Zn,Mn)O thin films: Effects of substrate temperature

We report on the observation of remarkable room-temperature ferromagnetism in epitaxial (Zn,Mn)O films grown by a pulsed-laser deposition technique using high-density targets. The optimum growth conditions were demonstrated from x-ray measurements, microstructure, Rutherford backscattering, micro-Raman, and magnetic studies. Superior ferromagnetic properties were observed in (Zn,Mn)O films grown at a substrate temperature of 500 °C and with an oxygen partial pressure of 1 mTorr. Ferromagnetism becomes weaker with increasing substrate temperature due to the formation of isolated Mn clusters irrespective of higher crystalline quality of the film