Simultaneous determination of elastic and structural properties under simulated mantle conditions using multi-anvil device MAX80

Abstract

An ultrasonic interferometry high-pressure set-up for elastic wave velocity measurements under simulated Earth's mantle conditions has been developed. A DIA-type multi-anvil apparatus MAX80 permanently located at HASYLAB, Hamburg, Germany for X-ray diffraction (XRD) under in situ condition was equipped for simultaneous ultrasonic measurements. Two of the six anvils were equipped with lithium niobate P-and S-wave transducers of 33.3 MHz natural frequency. The pressure and temperature limits of the high-pressure apparatus were not reduced as a side effect of the modification. The ultrasonic configuration allows all kinds of interferometric measurements with compressional and shear waves. In addition to the classical ultrasonic interferometry the newly developed data transfer function technique (DTF), first described in [J. Phys. Condens. Matter 14 (2002) 11337], is discussed in detail to give the readers the chance to use this valuable and important new method.The results for natural San Carlos olivine up to 3 GPa pressure are compared with published data of several authors. The data for hot-isostatic-pressed anorthite solved discrepancies between published high-pressure and normal-pressure data for polycrystalline anorthite leading to v p ¼ 7.28 km/s, v s ¼ 3.93 km/s at ambient conditions and dv p =dp ¼ 0.027 km/s GPa, dv s =dp ¼ 0.001 km/s GPa. The obtained data sets correspond to published results within the accuracy of the method.As an example for unquenchable phase transitions we measured the elastic wave velocities at the high-pressure clinoenstatite (MgSiO 3 , HCEn) -low-pressure (LCEn) transition at high pressure, high temperature conditions in conjunction with in situ XRD. For ultrasonic interferometry experiments LCEn powder synthesized at ambient pressure was hot-isostatic-pressed at 0.4 GPa and 14008C for 2 h in MAX80 to obtain low-porosity samples. The elastic wave velocities v p and v s of the CEn sample were measured in situ using the classical interferometric technique as well as the recently developed ultrasonic data transfer function (DTF) technique for the elastic wave velocities as a function of pressure at 7008C. To compare the results, v p and v s were measured at 6.7 and 7.5 GPa using both interferometric techniques. The results correspond within the limits of less than 1%.

Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration

“…X‐ray diffraction data were collected using a solid state Germanium detector analyzed by a multichannel analyzer (MCA). Techniques of high‐pressure ultrasonic interferometry have been discussed in detail in previous studies [e.g., Liebermann and Li , 1998; Kung et al , 2002; Li et al , 2004; Mueller et al , 2005]. Briefly, the sample was surrounded by NaCl+BN on its side and bottom surface to provide pseudohydrostatic stress conditions; it was then placed inside a cylindrical graphite heater located in the middle of the pressure medium made of precompressed Boron epoxy cube (6.15mm edge length).…”

“…A dual mode transducer was used to excite and receive P and S waves simultaneously at the same time when X‐ray diffraction spectrum was taken from the sample. A transfer function method was employed to record the acoustic response of the sample assemblage from which the travel time inside the sample is obtained by off‐line analyses [ Li et al , 2002; Mueller et al , 2005]. The distance the elastic wave traveled (i.e., the length of the sample) was directly monitored by an X radiographic imaging system which has been described in detail elsewhere [e.g., Li et al , 2004; Kung et al , 2002].…”

High-pressure falling sphere viscosimetry of basaltic and dacitic rocks in conjunction with synchrotron radiation

“…The experiments were performed in the single-stage multi-anvil DIA-device MAX80 installed at beamline F2.1 at DESY / HASYLAB, Hamburg; Germany (Mueller et al, 2005a(Mueller et al, , b, 2006(Mueller et al, , 2007. The apparatus is made up of a 2500 N hydraulic ram with two load frames driving four reaction bolsters for the lateral anvils ( Fig.…”