A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heate...A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 ℃ by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power-temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 ℃ under the pressure of 20 GPa.展开更多
In the present work, a third form, the so-called HP-BiNbO4 synthesized at high pressure and high temperature is investigated with the in-situ angle-dispersive x-ray diffraction（ADXRD） measurements under high pressur...In the present work, a third form, the so-called HP-BiNbO4 synthesized at high pressure and high temperature is investigated with the in-situ angle-dispersive x-ray diffraction（ADXRD） measurements under high pressure. We explore the compression behavior and phase stability of HP-BiNbO4. The structure of HP-BiNbO4 is first determined. The x-ray diffraction data reveal that the structure HP-BiNbO4 is stable under pressures up to 24.1 GPa. The ADXRD data yield a bulk modulus Ko = 185（7） GPa with a pressure derivative Ko＇= 2.9（0.8）. Furthermore, the data are compared with those of other ABO4 compounds. The results show that the bulk modulus of HP-BiNbO4（about 185 GPa） is slightly higher than that of tetragonal BiVO4 and significantly greater than those of the tungstates and molybdates.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 51872189)the Fundamental Research Funds for the Central Universities, China (Grant No. 2018SCUH0022).
文摘A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 ℃ by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power-temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 ℃ under the pressure of 20 GPa.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51472171 and 11427810)the Chinese Academy of Sciences(Grant Nos.KJCX2-SW-NO3 and KJCX2-SW-N20)
文摘In the present work, a third form, the so-called HP-BiNbO4 synthesized at high pressure and high temperature is investigated with the in-situ angle-dispersive x-ray diffraction（ADXRD） measurements under high pressure. We explore the compression behavior and phase stability of HP-BiNbO4. The structure of HP-BiNbO4 is first determined. The x-ray diffraction data reveal that the structure HP-BiNbO4 is stable under pressures up to 24.1 GPa. The ADXRD data yield a bulk modulus Ko = 185（7） GPa with a pressure derivative Ko＇= 2.9（0.8）. Furthermore, the data are compared with those of other ABO4 compounds. The results show that the bulk modulus of HP-BiNbO4（about 185 GPa） is slightly higher than that of tetragonal BiVO4 and significantly greater than those of the tungstates and molybdates.
