Development of induction heating diamond anvil cell and its application to Raman micro- spectroscopy.

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16540441
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Osaka City University
• Principal Investigator: SHINODA Keiji Osaka City University, Graduate School of Science, Lecture, 大学院・理学研究科, 講師 (40221296)
• Co-Investigator(Kenkyū-buntansha): KATSURA Tomoo Okayama University, Institute for Study of the Earth's Interior, Assistant Professor, 地球物質科学研究センター, 助教授 (40260666)
• Project Period (FY): 2004 – 2005
• Keywords: Induction heating / diamond anvil cell / Raman microspectroscopy / coesite / quartz

Research Abstract

A high temperature diamond anvil cell by high frequency induction heating (IH-DAC) was newly constructed for Raman microspectroscopy. DAC is widely used high pressure apparatus to investigate the depth of the Earth. In this project, a high frequency induction heating was adopted to elevate temperature of DAC. The IH-DAC will possibly be a modified external heating method to heat DAC stably. The IH-DAC was designed as modifying the Merrill-Bassett DAC as to apply pressure with a lever. One turn of induction coil of Cu made for IH-DAC surrounds a pair of diamonds. The temperature of a sample in gasket can be directly measured by Raman spectra. The intensities of Stokes (I_S) and anti-Stokes (I_<aS>) lines are related by the Boltzmann factor as I_<aS>/I_S=exp(-hv/kT). Stokes and anti-Stokes lines of silicon were used for calibration of temperature.
After several preliminary experiments of heating dummy plates of SUS, WC and Re by IH, WC rockers and Re gasket were selected for IH-DAC. Heating directly rockers by IH is hopeful way to attain high temperature over 1000℃. IH-DAC is a workable method for HT-HP experiments. A phase transformation from quartz to coesite was directly observed under IH-DAC. The transformation rates were estimated from intensities of Raman peak of quartz and coesite. From the relation between experimental time and the transformation rate, a transformation mechanism was discussed.