Measurements of acoustic wave velocities at P-T conditions of the Earth's mantle

1998 ◽  
pp. 119-128 ◽  
Author(s):  
Ruth Knoche ◽  
Sharon L. Webb ◽  
David C. Rubie
Keyword(s):  
Acoustic Wave ◽  
Earth’S Mantle ◽  
Wave Velocities

Contactless ultrasonic device to measure surface acoustic wave velocities versus temperature

2007 ◽  
Vol 78 (2) ◽  
pp. 024901 ◽  
Author(s):  
C. Hubert ◽  
M.-H. Nadal ◽  
G. Ravel-Chapuis ◽  
R. Oltra
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Ultrasonic Device ◽  
Wave Velocities

scholarly journals Theoretical investigation of acoustic wave velocity of aluminum phosphide under pressure

2019 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Salah Daoud ◽  
Abdelhakim Latreche ◽  
Pawan Kumar Saini
Keyword(s):  
Acoustic Wave ◽  
Wave Velocity ◽  
Elastic Constants ◽  
Structural Parameters ◽  
Theoretical Data ◽  
Aluminum Phosphide ◽  
Semiconducting Material ◽  
Wave Velocities ◽  
Knoop Microhardness ◽  
Good Agreement

The bulk and surface acoustic wave velocities of Aluminum phosphide (AlP) semiconducting material under pressure up to 9.5 GPa were studied. The structural parameters and the elastic constants used in this work are taken from our previous paper published in J. Optoelec-tron. Adv. M. 16, 207 (2014). The results obtained at zero-pressure are analyzed and compared with other data of the literature. In addition, the acoustic Grüneisen parameter and the Vickers and Knoop microhardness are predicted and analyzed in detail. Our calculated results are in good agreement with the experimental and other theoretical data of literature.   

Microhardness, phase transition, acoustic wave velocities and melting temperature of AlxGa1−xSb

2018 ◽  
Vol 32 (20) ◽  
pp. 1850210 ◽  
Author(s):  
O. A. Al-Hagan ◽  
H. Algarni ◽  
N. Bouarissa ◽  
M. Ajmal Khan ◽  
T. F. Alhuwaymel
Keyword(s):  
Acoustic Wave ◽  
Melting Temperature ◽  
Composition Dependence ◽  
Ternary Alloys ◽  
Virtual Crystal Approximation ◽  
Al Content ◽  
Wave Velocities ◽  
Good Accord ◽  
Compositional Disorder ◽  
Pseudopotential Approach

The band structure of Al[Formula: see text]Ga[Formula: see text]Sb semiconducting ternary alloys and their related properties such as elastic constants, microhardness, transition pressure to the first phase, acoustic wave velocities and melting temperature have been investigated. The calculations are performed using a pseudopotential approach within the virtual crystal approximation which includes the effect of compositional disorder as an effective potential. Generally, our results are found to be in good accord with the experimental results. The composition dependence of all features of interest showed a monotonic behavior and suggests that the stiffness, hardness and structural stability becomes better in Al[Formula: see text]Ga[Formula: see text]Sb for higher Al concentrations. The bulk sound speeds and melting temperature are found to become larger when increasing the Al content.

ELASTIC CONSTANTS AND ACOUSTIC WAVE VELOCITIES IN Cd1-xZnxTe MIXED CRYSTALS

2008 ◽  
Vol 22 (12) ◽  
pp. 1221-1229 ◽  
Author(s):  
N. BOUARISSA ◽  
Y. ATIK
Keyword(s):  
Acoustic Wave ◽  
Elastic Constants ◽  
Mixed Crystals ◽  
Bulk Acoustic Wave ◽  
Virtual Crystal Approximation ◽  
Wave Speeds ◽  
Wave Velocities ◽  
Zinc Blende ◽  
Compositional Disorder ◽  
Zinc Blende Structure

Based on the pseudopotential scheme under the virtual crystal approximation that takes into account the effect of compositional disorder combined with the bond-orbital model of Harrison, the results of calculations of elastic constants and surface and bulk acoustic wave speeds of Cd 1-x Zn x Te mixed crystals in the zinc-blende structure are presented. The agreement between our results and known data, which are only available for CdTe and ZnTe is found to be reasonable.

An instrument for measuring acoustic wave velocities in metals and alloys

2016 ◽  
Vol 59 (3) ◽  
pp. 476-480 ◽  
Author(s):  
V. V. Murav’ev ◽  
D. V. Zlobin ◽  
S. V. Len’kov ◽  
N. N. Zverev
Keyword(s):  
Acoustic Wave ◽  
Metals And Alloys ◽  
Wave Velocities

scholarly journals Wave Velocities in the Outer Part of the Earth's Mantle

Nature ◽  
1952 ◽  
Vol 170 (4320) ◽  
pp. 289-289 ◽  
Author(s):  
B. GUTENBERG
Keyword(s):  
Outer Part ◽  
Earth’S Mantle ◽  
Wave Velocities

Sequential Measurement of Compressional and Shear Velocities of Rock Samples Under Triaxial Pressure

1969 ◽  
Vol 9 (04) ◽  
pp. 378-394 ◽  
Author(s):  
K.P. Desai ◽  
D.P. Helander
Keyword(s):  
Acoustic Wave ◽  
Resonant Frequency ◽  
Wave Velocity ◽  
Resonance Method ◽  
Shear Velocity ◽  
Berea Sandstone ◽  
Rock Samples ◽  
Wave Velocities ◽  
Compressional Velocity ◽  
Wave Properties

Abstract A laboratory measuring system was designed that can precisely and sequential measure both compressional and shear velocities of rock samples under identical conditions of stress distribution and stress history. This is required if accurate and realistic dynamic elastic properties of rocks are to be determined. The hysteresis effect on velocity pressure characteristics of rock was determined to pressure characteristics of rock was determined to illustrate this point. Lead titanate zirconate transducers were used for measuring compressional wave velocity, and AC-cut quartz transducers were used for measuring shear wave velocity. The system was tested using samples of standard material such as aluminum, steel, brass and lucite. Measurements obtained were accurate within 1 percent. percent. Compressional and shear velocities were measured sequentially on 10 samples of Berea sandstone and two samples of Bartlesville sandstone. It was found that 1. Both compressional and shear velocities increased with an increase in applied external pressure. pressure. 2. Compressional velocity depends upon both external (Pe) and internal (Pi) pressure. 3. Shear velocity depends only upon the differential pressure (Pne-Pe-Pi). 4. The nature of the fluid saturant had little effect on compressional velocity. 5. Shear velocity decreased with an increase in the density of the saturant. 6. The Berea sandstone indicated very little anisotropy. 7. The Bartlesville sandstone showed definite anisotropy. Introduction The various properties of an acoustic wave trainvelocity, amplitude, frequency, etc. may be modified, sometimes quite severely by the media through which the wave has traveled. This suggests the use of wave properties to determine, at least in part, the nature of the material through which the part, the nature of the material through which the wave has passed. To accomplish this successfully requires a reliable technique to for obtaining accurate values of all acoustic wave properties. One purpose of this paper is to describe a recently developed system that can precisely and sequentially record acoustic compressional and shear energies as functions both of time and of frequency. One example of the utility of this system is the accurate measurement of compressional and shear velocities through rock samples subjected to triaxial, i.e., simultaneous but independent vertical, circumferential and pore pressure. Since acoustic velocity and elasticity are closely interrelated, such a system would help to determine realistically the elastic properties of rock samples in the laboratory. METHODS FOR THE INDEPENDENT MEASUREMENT OF COMPRESSIONAL AND SHEAR WAVE VELOCITIES Currently there are two suitable nondestructive laboratory techniques for measuring wave velocity through a rock sample under pressure. One is by the resonance method and the other is by the pulse technique. In the resonance method a sample, in the form of a thin wire, rod, or plate, is make to vibrate in the longitudinal, torsional or flexural mode. Resonant frequency is determined by recording the amplitude of vibration as a function of applied frequency; the amplitude is maximum at resonant frequency. For isotropic materials the relationships between resonance frequencies, elastic moduli and acoustic wave velocities are well known. SPEJ p. 378

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