【摘 要】
:
The heat capacities of three ternary compounds, K2Ca2Si2O7, K4CaSi3O9, and K8CaSi10O25 are measured by this drop mode from MHTC96.The samples are prepared by Dr.V..Kahlenberg from University of Innsbr
【机 构】
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School of Materials Science and Engineering, Central South University, Changsha, 410083;TU Bergakade
【出 处】
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第十七届全国相图学术会议暨相图与材料设计国际研讨会
论文部分内容阅读
The heat capacities of three ternary compounds, K2Ca2Si2O7, K4CaSi3O9, and K8CaSi10O25 are measured by this drop mode from MHTC96.The samples are prepared by Dr.V..Kahlenberg from University of Innsbruck of Austria.Dried K2CO3 (AlfaAesar, puratronic), CaCO3 (AlfaAesar, 99.995 %) and SiO2 (AlfaAesar, 99.995 %) are used as starting materials for the synthesis experiments.Each composition has been synthesized via solid state reactions.Thereafter, a stoichiometric mixture of the dried educts in themolar ratios based on the composition is homogenized in a planetary mill under ethanol, dry for several hours at 60 ℃ and pressed into pellets.The discs are subsequently heated in a platinum crucible covered with a lid from 300 ℃ to 900 ℃ with a ramp of 50 ℃/h, hold at this temperature for 78 h and eventually quench in air.A preliminary X-ray powder diffraction pattern of the product is applied to confirm that these samples are pure compounds.These samples are sensitive to environment, especially moisture, so they need to be used as soon as possible.And They are powders, however, in drop model,powder is not possible.Then, they should be press to pellets, which lead to these samples very fragile, it should handle very carefully during weighing and actual drop.
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