High-pressure generation by a multiple anvil system with sintered diamond anvils and study of pressure measurement

(1)烧结金刚石多砧系统高压发电。二级MA8高压系统的顶锤采用烧结金刚石，一级MA6高压系统的顶锤采用碳化钨顶锤。烧结金刚石块（SYNDAX L555, De Beers diamond Co. Ltd）用碳化硅胶结，因此，复合材料对x射线束具有优异的透明度。所述烧结金刚石被抛光成立方体，其角被截断以形成MA8装置的砧头。截边长度为0.5 mm和1.0 mm。对于TEL= 1.0 mm的铁砧，镁质压力介质的八面体边缘长度为3.4mm。通过测量金的晶格常数来确定产生的压力。压力产生高达28GPa的TEL= 1。0mm和41GPa的TEL=0.5mm。为了在更大的体积中获得更高的压力，我们必须明确三个因素，即1)更大的力，2)材料的高强度，3)强度的大压力导数。没有磨粉机的烧结金刚石可以明确这三个因素，但不可能得到它。将烧结好的金刚石块（SYNDIE, 1285/D27, De Beers diamond Co. Ltd）打磨成立方体，将其棱角截断，形成MA8仪器的砧头。抛光后的烧结金刚石立方体的侧面长度为8.45mm。目前使用的铁砧截边长度（TEL）为2mm。在这种情况下，很容易产生高达28GPa的压力（Fe85%V%15 α - epsilon转变），但砧头的压力增加到6GPa，因此，不可能增加压力。(3) 64型高压装置本实验使用的高压系统由8块组成。一个块由一个烧结金刚石砧（8.45毫米）和7个WC立方砧（8毫米）组成。金属垫片放在两个套管之间。系统由DIA-30压紧。在Fe80%V20%的最小电阻点的基础上，获得了超过35GPa的压力。少

(1) High-pressure generation by a multiple anvil system with sintered diamond. Sintered diamonds are employed for the anvil of second-stage MA8 high pressure system and the anvil of fist stage is used tungsten carbide anvil for MA6 system. The sintered diamond blocks (SYNDAX L555, De Beers Diamond Co. Ltd) are cemented with silicon carbide, therefore, the composites have excellent transparency for the x-ray beam. The sintered diamonds are polished to form cubes and their corner are truncated to form the anvil head of the MA8 apparatus. The truncated edge lengths are 0.5 and l.0mm. The edge length of the octahedron of the magnesia pressure medium is 3.4mm for the anvil with TEL=l.0mm. The pressure generated was determined by measuring the lattice constant of gold. Pressures generated up to 28GPa for TEL=l.0mm and 41GPa for TEL=0.5mm.(2) High pressure generation In large volume In order to attain higher pressure in larger volume, we have to clear three factors, that is, 1) the large forc … More e utilized, 2) high strength of material, and also 3) the large pressure derivative of strength. The no bander sintered diamond can be clear the three factors, but it is not possible to get it. The sintered diamond blocks (SYNDIE, 1285/D27, De Beers Diamond Co. Ltd) are polished to form cubes, and their corners are truncated to form the anvil head of the MA8 apparatus. A side of a sintered diamond cube after polishing has 8.45mm in length. The truncated edge length(TEL)of the anvil used for the present is 2mm. In this case, it is easy to generate pressure up to 28GPa(Fe85%V%15 alpha - epsilon transition), but press of the anvil head increase up to 6GPa, therefore, it is not possible to increase pressure.(3) 64-type high pressure apparatus The high pressure system used present experimentare constituted with eight blocks. A block is consisted with one sintered diamond anvile (8.45mm) and 7 pieces of WC cubic(8mm) anvils. Metal gaskets are put in between the an vils. The system is pressed by DIA-30. Pressures in excess of 35GPa were obtained on the basis of minimum point of electrical resistance of the Fe80%V20%. Less