Effect of crystal structure characteristics of mineral formations on anisotropy of the speed of ultrasonic waves

The structure characteristics, temperature and concentration dependences of the electrical resistivity and the thermopower coefficient for the Vx+yCo1-ySb3 skutterudite were investigated in the ranges: T = 80 - 400 K, x = 0.02 - 0.20. It was shown that the introduction of V atoms into the structure of CoSb3 thermoelectric material was accompanied by an increase in the efficiency of conversion of thermal energy into electrical energy. It was established that the inversion in the sign of the thermopower coefficient for Vx+yCo1-ySb3 not observed for these concentrations of V impurity atoms. Based on the analysis of electrokinetic and energy state characteristics of Vx+yCo1-ySb3, it was assumed that the V (3d34s2) impurity atoms simultaneously replaced Co (3d74s2)atoms, generating structural defects of acceptor nature, and were located in the icosahedral voids of the crystal structure and generated donors.

Download Full-text

Influence of nacre thickness and crystal structure characteristics on interference color and luster of cultured Akoya pearl

NIPPON SUISAN GAKKAISHI ◽

10.2331/suisan.20-00071 ◽

2021 ◽

Author(s):

HIDEO AOKI ◽

MICHIO SUZUKI ◽

SHINJI TANAKA ◽

TAKASHI ATSUMI ◽

SHIGEKI NAKAUCHI ◽

...

Keyword(s):

Crystal Structure ◽

Structure Characteristics ◽

Interference Color

Download Full-text

One step sonochemical synthesis of single phase Sr-doped ZnO2 nanorods

SN Applied Sciences ◽

10.1007/s42452-021-04479-7 ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Deepesh Bhardwaj ◽

Dixit Prasher ◽

Anuj Dubey ◽

Vishal Dhiman ◽

Radha Tomar

Keyword(s):

Crystal Structure ◽

Chemical Method ◽

Single Phase ◽

Ultrasonic Waves ◽

Nano Composites ◽

Sonochemical Synthesis ◽

Structure Morphology ◽

One Step ◽

Uv Visible ◽

Average Size

Abstract Single phase SrZnO2 nanorods with average size of around 100 nm are synthesized by probe sonicator using ultrasonic waves at 60 W, 6 kHz for 3 h to observe the changes in optoelectronic properties of ZnO. The as grown SrZnO2 has a single phase rod shaped structure. These nanorods were broadly characterized by different instrumental techniques like TEM, FESEM, EDAX, XRD, UV–Visible and FTIR for analysis of size, crystal structure, morphology and composition which acknowledge the formation of single phase crystalline ZnO and slightly amorphous SrZnO2 nanorods. All these results suggest that single phase SrZnO2 nano-composites can easily be synthesized by one step sono-chemical method. Graphic abstract

Download Full-text

Crystal growth and influence of the crystal structure characteristics on the shock sensitivities of RDX, HMX and CL-20 nitramine explosives

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767313097626 ◽

2013 ◽

Vol 69 (a1) ◽

pp. s276-s276

Author(s):

Hongzhen Li ◽

Rong Xu ◽

Bing Kang ◽

Jinshan Li ◽

Xiaoqing Zhou ◽

...

Keyword(s):

Crystal Structure ◽

Crystal Growth ◽

Structure Characteristics

Download Full-text

Frictional Performance of Brake Pads against Al Metal Matrix Composites with Different Sizes of SiC Particles

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1743 ◽

2007 ◽

Vol 336-338 ◽

pp. 1743-1745

Author(s):

Shao Yang Zhang ◽

Fu Ping Wang

Keyword(s):

Crystal Structure ◽

Friction Coefficient ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Elevated Temperatures ◽

Matrix Composites ◽

Brake Pads ◽

Structure Characteristics ◽

Large Size ◽

Frictional Performance

Two drums suitable for a Chase Machine were made of Al metal matrix composites containing 25vol.% SiCp with 3.5 μm and 34 μm in nominal diameter respectively. The same brake pads were measured on the Chase Machine installing each individual drum. It has been found that the brake pads had better frictional performance and wear resistance against the drum with the large-size SiCp than against the drum with the small-size ones. Friction fade took place at elevated temperatures - above 316 oC, but the original level of friction coefficient could be regained rapidly upon cooling with regard to the latter. The minor level of friction coefficient was attributable to soft Al crystal structure characteristics and thick tribofilms during the testing stages.

Download Full-text