A far-infrared p-type germanium laser with active crystal prepared from ultra pure single-crystal Ge by neutron transmutation doping ~NTD! is demonstrated. Calculations show that the high uniformity of Ga acceptor distribution achieved by NTD significantly improves average gain. The stronger ionized impurity scattering due to high compensation in NTD Ge is shown to have insignificant negative i...

We have investigated features of liquid crystalline materials for organic polycrystalline field effect transistors (OFETs) with a model liquid crystalline material of 5,5”-dioctylterthiophene (8-TTP-8). Bulk mobility in polycrystalline thin films of 8-TTP-8 via its liquid crystalline phase was easily determined by time-of-flight experiments. Furthermore, we could evaluate impurity contamination...

Some impurities cannot integrate into isolated kinks because they completely block the growth of to which adsorb. For this class impurity, we derive an equation for amount that incorporates a crystal during elementary step by assuming such impurity if and only it gets captured between kink antikink. We show concentration in increases monotonically with mother phase, but can vary non-monotonical...

The temperature dependence o f 35C1 NQ R frequencies was measured on the mixed crystal [(NH 4)00|Kp99]2SnCl6. Two phase transitions have been located at 7"cl = 259K and J ’c2 = 252K, which are lower by 3 K than the corresponding transition temperatures o f the pure K2SnCl6 crystal. The DSC experiments showed that the NH^ concentration dependence o f ?c2 almost parallels that o f Tc]. The impuri...

Background: The “pasta” phase of nuclear matter may play an important role in the structure and evolution of neutron stars. Recent works suggest nuclear pasta has a high resistivity which could be explained by the presence of long-lived topological defects. The defects act as impurities that decrease thermal and electrical conductivity of the pasta. Purpose: To quantify how topological defects ...

When a hydrogen molecule in a parahydrogen crystal is excited to a high vibrational overtone state, its electronic properties vary significantly since the energy of excitation is a sizable fraction of the energies of the excited electronic states. Thus the vibrational excitation leads to a significant variation of the intermolecular potential and resultant local distortion of the crystal lattic...

Using general properties of the crystal site representation normal mode matrix, we provide some simple bounds on localized modes in crystals with point defects. I. DERIVATION OF THE TRACE CONDITION The substitutional insertion of a point defect impurity into an otherwise perfect crystal will typically (see e.g. [1]) modify the spectrum of the 3N normal modes of the crystal, leading in certain c...