TY - JOUR
T1 - A new 6-axis apparatus to squeeze the Kawai-cell of sintered diamond cubes
AU - Ito, Eiji
AU - Katsura, Tomoo
AU - Yamazaki, Daisuke
AU - Yoneda, Akira
AU - Tado, Masashi
AU - Ochi, Takahiro
AU - Nishibara, Eiichi
AU - Nakamura, Akihiro
N1 - Funding Information:
The 6-axis apparatus was constructed by a fund from the Ministry of Education, Culture, Sports, Science, Technology, and Sports of the Japanese Government. The authors are very grateful to Max Schmidt and an anonymous reviewer for their constructive comments.
PY - 2009/5
Y1 - 2009/5
N2 - In order to overcome disadvantages of the DIA type press in squeezing the Kawai-cell, such as uneven compression between the upper and lower anvils and the four surrounding anvils and frictional loss of applied load in the guide block, we have developed a new 6-axis apparatus in which the movements of the six anvils are controlled by a servo mechanism. It is possible to keep the Kawai-cell cubic within an accuracy of ±2 μm during compression and decompression. Pressure generation using sintered diamond cubic anvils with edge length of 14.0 mm and a truncation of 1.5 mm has been carried out up to ca. 60 GPa by measuring electrical resistance of GaP, Zr, and Fe2O3. The results are compared with our previous calibration, carried out using an almost the same sample setup for identical anvils at SPring-8, by means of in situ X-ray observation. It is demonstrated that a significant amount of the applied load is lost by friction when the Kawai-cell is squeezed in the DIA type press. The load loss increases with increasing load, or pressure, and amounts to 45% at ca. 60 GPa. Therefore the 6-axis apparatus is very advantageous to generate higher pressures in the Kawai-cell. However, individual control of the anvils sometimes induces a runaway advancement of the anvils which brings about an abrupt increase of pressure.
AB - In order to overcome disadvantages of the DIA type press in squeezing the Kawai-cell, such as uneven compression between the upper and lower anvils and the four surrounding anvils and frictional loss of applied load in the guide block, we have developed a new 6-axis apparatus in which the movements of the six anvils are controlled by a servo mechanism. It is possible to keep the Kawai-cell cubic within an accuracy of ±2 μm during compression and decompression. Pressure generation using sintered diamond cubic anvils with edge length of 14.0 mm and a truncation of 1.5 mm has been carried out up to ca. 60 GPa by measuring electrical resistance of GaP, Zr, and Fe2O3. The results are compared with our previous calibration, carried out using an almost the same sample setup for identical anvils at SPring-8, by means of in situ X-ray observation. It is demonstrated that a significant amount of the applied load is lost by friction when the Kawai-cell is squeezed in the DIA type press. The load loss increases with increasing load, or pressure, and amounts to 45% at ca. 60 GPa. Therefore the 6-axis apparatus is very advantageous to generate higher pressures in the Kawai-cell. However, individual control of the anvils sometimes induces a runaway advancement of the anvils which brings about an abrupt increase of pressure.
KW - A 6-axis apparatus
KW - A servo mechanism
KW - Pressure generation
KW - Sintered diamond
KW - The Kawai-cell
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U2 - 10.1016/j.pepi.2008.11.007
DO - 10.1016/j.pepi.2008.11.007
M3 - Article
AN - SCOPUS:67349104658
SN - 0031-9201
VL - 174
SP - 264
EP - 269
JO - Physics of the Earth and Planetary Interiors
JF - Physics of the Earth and Planetary Interiors
IS - 1-4
ER -