Effect of lattice distortion on impurity modes

1978 ◽  
Vol 11 (2) ◽  
pp. 241-244 ◽  
N Chandralekha Devi ◽  
S N Behera
M.F. Schmid ◽  
R. Dargahi ◽  
M. W. Tam

Electron crystallography is an emerging field for structure determination as evidenced by a number of membrane proteins that have been solved to near-atomic resolution. Advances in specimen preparation and in data acquisition with a 400kV microscope by computer controlled spot scanning mean that our ability to record electron image data will outstrip our capacity to analyze it. The computed fourier transform of these images must be processed in order to provide a direct measurement of amplitudes and phases needed for 3-D reconstruction.In anticipation of this processing bottleneck, we have written a program that incorporates a menu-and mouse-driven procedure for auto-indexing and refining the reciprocal lattice parameters in the computed transform from an image of a crystal. It is linked to subsequent steps of image processing by a system of data bases and spawned child processes; data transfer between different program modules no longer requires manual data entry. The progress of the reciprocal lattice refinement is monitored visually and quantitatively. If desired, the processing is carried through the lattice distortion correction (unbending) steps automatically.

2020 ◽  
Yuan-Yuan Tan ◽  
Ming-Yao Su ◽  
Zhou-Can Xie ◽  
Zhong-Jun Chen ◽  
Yu Gong ◽  

2021 ◽  
pp. 110877
Ankit Roy ◽  
Praveen Sreeramagiri ◽  
Tomas Babuska ◽  
Brandon Krick ◽  
Pratik K. Ray ◽  

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1564
Jin Hee Kim ◽  
Song Yi Back ◽  
Jae Hyun Yun ◽  
Ho Seong Lee ◽  
Jong-Soo Rhyee

We investigated the anisotropic thermoelectric properties of the Bi2Te2.85Se0.15Ix (x = 0.0, 0.1, 0.3, 0.5 mol.%) compounds, synthesized by ball-milling and hot-press sintering. The electrical conductivities of the Bi2Te2.85Se0.15Ix were significantly improved by the increase of carrier concentration. The dominant electronic scattering mechanism was changed from the mixed (T ≤ 400 K) and ionization scattering (T ≥ 420 K) for pristine compound (x = 0.0) to the acoustic phonon scattering by the iodine doping. The Hall mobility was also enhanced with the increasing carrier concentration. The enhancement of Hall mobility was caused by the increase of the mean free path of the carrier from 10.8 to 17.7 nm by iodine doping, which was attributed to the reduction of point defects without the meaningful change of bandgap energy. From the electron diffraction patterns, a lattice distortion was observed in the iodine doped compounds. The modulation vector due to lattice distortion increased with increasing iodine concentration, indicating the shorter range lattice distortion in real space for the higher iodine concentration. The bipolar thermal conductivity was suppressed, and the effective masses were increased by iodine doping. It suggests that the iodine doping minimizes the ionization scattering giving rise to the suppression of the bipolar diffusion effect, due to the prohibition of the BiTe1 antisite defect, and induces the lattice distortion which decreases lattice thermal conductivity, resulting in the enhancement of thermoelectric performance.

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23719-23724
Md. Lokman Ali

The effect of transition-metals (TM) addition on the mechanical properties of CrCoNi medium entropy alloys (MEAs) was investigated.

2021 ◽  
pp. 117135
Hyun Seok Oh ◽  
Khorgolkhuu Odbadrakh ◽  
Yuji Ikeda ◽  
Sai Mu ◽  
Fritz Körmann ◽  

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