High Pressure Electrical Conductivity in Naturally Occurring Silicate Liquids

Author(s):  
James A. Tyburczy ◽  
Harve S. Waff
Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 746
Author(s):  
Meiling Hong ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Xinyu Zhang

A series of investigations on the structural, vibrational, and electrical transport characterizations for Ga2Se3 were conducted up to 40.2 GPa under different hydrostatic environments by virtue of Raman scattering, electrical conductivity, high-resolution transmission electron microscopy, and atomic force microscopy. Upon compression, Ga2Se3 underwent a phase transformation from the zinc-blende to NaCl-type structure at 10.6 GPa under non-hydrostatic conditions, which was manifested by the disappearance of an A mode and the noticeable discontinuities in the pressure-dependent Raman full width at half maximum (FWHMs) and electrical conductivity. Further increasing the pressure to 18.8 GPa, the semiconductor-to-metal phase transition occurred in Ga2Se3, which was evidenced by the high-pressure variable-temperature electrical conductivity measurements. However, the higher structural transition pressure point of 13.2 GPa was detected for Ga2Se3 under hydrostatic conditions, which was possibly related to the protective influence of the pressure medium. Upon decompression, the phase transformation and metallization were found to be reversible but existed in the large pressure hysteresis effect under different hydrostatic environments. Systematic research on the high-pressure structural and electrical transport properties for Ga2Se3 would be helpful to further explore the crystal structure evolution and electrical transport properties for other A2B3-type compounds.


2016 ◽  
Vol 174 (3) ◽  
pp. 1033-1041 ◽  
Author(s):  
KeShi Hui ◽  
LiDong Dai ◽  
HePing Li ◽  
HaiYing Hu ◽  
JianJun Jiang ◽  
...  

1980 ◽  
Vol 60 (3) ◽  
pp. 903-910 ◽  
Author(s):  
M. R. CARTER

Greenhouse and field studies were conducted to assess the salinity tolerance of Siberian larch (Larix siberica L.) under conditions found on the Canadian prairies. In greenhouse studies top and root growth of Siberian larch seedlings began to decline under sulphate salinity between 2.0 and 5.3 mmhos/cm (electrical conductivity of saturation paste extract) indicating that Siberian larch is moderately salt-tolerant. The addition of chloride caused an initial top growth decrease, chlorosis, and reduction in survival between 1.4 and 3.6 mmhos/cm; the latter salinity level being associated with 20 meq/L of Cl and 1.5% Cl in the saturation paste extract and needles, respectively. Field studies conducted under naturally occurring sulphate salinity indicated that height of 10-yr-old Siberian larch began to decline between 3.5 and 4.0 mmhos/cm. Changes in needle mineral composition were related to the ratio or increase of ions in the soil solution, and the physiological effect of the sulphate and chloride anion. In general, presence of chloride salinity caused a greater increase to occur in the cation content of the needles than sulphate salinity. Accumulation of organic anions in the needles was also related to cation concentration and needle chlorosis.


1996 ◽  
Vol 57 (2) ◽  
pp. 211-216 ◽  
Author(s):  
Ichimin Shirotani ◽  
Takafumi Adachi ◽  
Kenji Tachi ◽  
Sakae Todo ◽  
Kiyokazu Nozawa ◽  
...  

2020 ◽  
Vol 310 ◽  
pp. 6-13
Author(s):  
Vadim V. Efremov ◽  
Mikhail N. Palatnikov ◽  
Yuriy V. Radyush ◽  
Olga B. Shcherbina

Ferroelectric ceramic solid solutions LixNa1-xTayNb1-yO3 (х = 0.17; у = 0 – 0.5) with the perovskite structure have been obtained by the thermobaric synthesis method. Particularities of their microstructure, elastic properties, electrical conductivity and permittivity have been researched. It has been established that an increase in the thermobaric synthesis temperature leads to a decrease in the Young’s modulus value. Specific static conductivity values have been determined; charge carrier activation enthalpies На have been calculated. The Curie temperature of the samples has been determined to decrease with an increase in tantalum content. A Ferroelectric ceramic solid solution Li0.17Na0.83Ta0.1Nb0.9O3 was shown to undergo four structure phase transitions in the temperature range 300-820 К. A Li0.17Na0.83Ta0.1Nb0.9O3 has been shown to be a high temperature superionic. Possible mechanisms of the detected phenomena are discussed.


Materialia ◽  
2020 ◽  
Vol 14 ◽  
pp. 100916 ◽  
Author(s):  
Yongpeng Tang ◽  
Takuya Komatsu ◽  
Takahiro Masuda ◽  
Makoto Arita ◽  
Yoichi Takizawa ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 75 ◽  
Author(s):  
Linfei Yang ◽  
Lidong Dai ◽  
Heping Li ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  

The phase stability of epsomite under a high temperature and high pressure were explored through Raman spectroscopy and electrical conductivity measurements in a diamond anvil cell up to ~623 K and ~12.8 GPa. Our results verified that the epsomite underwent a pressure-induced phase transition at ~5.1 GPa and room temperature, which was well characterized by the change in the pressure dependence of Raman vibrational modes and electrical conductivity. The dehydration process of the epsomite under high pressure was monitored by the variation in the sulfate tetrahedra and hydroxyl modes. At a representative pressure point of ~1.3 GPa, it was found the epsomite (MgSO4·7H2O) started to dehydrate at ~343 K, by forming hexahydrite (MgSO4·6H2O), and then further transformed into magnesium sulfate trihydrate (MgSO4·3H2O) and anhydrous magnesium sulfate (MgSO4) at higher temperatures of 373 and 473 K, respectively. Furthermore, the established P-T phase diagram revealed a positive relationship between the dehydration temperature and the pressure for epsomite.


Sign in / Sign up

Export Citation Format

Share Document