Title :
Elastic properties of the [N(CH3)4]2 XCl4 (X=Co,Zn,Cu,Mn) crystals-possible application
Author :
Vlokh, O.G. ; Kityk, A.V. ; Mokry, O.M.
Author_Institution :
Lvov State Univ., Ukraine
Abstract :
Summary form only given. Crystals of the [N(CH3)4 ]2XCl4 class (X=Co,Zn,Cu,Mn) undergo a sequence of phase transitions (PTs), including PTs into the incommensurate, ferroelectric, and ferroelastic phases. The temperature dependence of the longitudinal and transverse ultrasonic wave velocities under the PTs was studied for this crystal by the pulse-echo method at a frequency of 10 MHz. Under the applied hydrostatic pressure significant changes of the temperature dependence character for the longitudinal and transverse elastic waves were found in the incommensurate phase. The results were explained phenomenologically, considering the interactions of elastic waves with normal coordinates of the incommensurate phase-phason and amplitudon
Keywords :
commensurate-incommensurate transformations; elastic waves; ferroelasticity; ferroelectric transitions; high-pressure effects in solids; organic compounds; ultrasonic velocity; 10 MHz; amplitudon; applied hydrostatic pressure; dimethylammonium tetrachlorides; elastic waves; ferroelastic; ferroelectric; incommensurate phase; phase transitions; phason; pulse-echo method; ultrasonic wave velocities; Crystals; Ferroelectric materials; Frequency; Phase modulation; Temperature dependence; Zinc;
Conference_Titel :
Applications of Ferroelectrics, 1990., IEEE 7th International Symposium on
Conference_Location :
Urbana-Champaign, IL
Print_ISBN :
0-7803-0190-0
DOI :
10.1109/ISAF.1990.200295
