Observation of ultrasound velocity gradient in fullerene ceramics by acoustic microscopy

• Published in: Ultrasonics Vol. 38; no. 1; pp. 327 - 330
• Main Authors: Berezina, Sofia, Blank, Vladimir, Levin, Vadim, Prokhorov, Vyacheslav
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-03-2000
• Subjects: Acoustic microscopy; Elastic properties; Fullerene; High pressure; Velocity gradient; Fullerene; Elastic properties; Acoustic microscopy; Velocity gradient; High pressure
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/S0041-624X(99)00210-3

A scanning acoustic microscope is used to study the distribution of elastic properties in small samples (∅ 3×2
mm
3) of new hard phases of C
60. The specimens under investigation were synthesized from pure C
60 powder under pressure
P=8
GPa in the temperature range 500–1650
K. The time-of-flight mode was used for bulk sound wave velocity determination in a direction parallel to the cylinder's axis. Longitudinal sound wave velocities greater than 10
000
m/s were found for all specimens treated at temperatures higher than 1000
K. Using the B-scan mode allowed us to observe the velocity gradient in the sample's periphery. The heterogeneous internal structure of the specimen is visualized in the images formed in C- and B-scan modes.