Temperature Dependence of the Material and Acoustic Wave Parameters of Berlinite

Origin and Mechanism of Piezoelectricity in α-Quartz-type MIIIXVO4 Compounds (M = B, Al, or Ga; X = P or As)

“…Their calculated values are listed in Table ( e 11 ) and Table ( e 14 ) for M III X V O 4 compounds (M = B, Al, or Ga and X = P or As). Reliable experimental values of the piezoelectric constants have been reported in AlPO 4 , and GaPO 4 and are in excellent agreement with our calculations. The piezoelectric stress constants of the other α-quartz isotypes remain experimentally unknown.…”

“…The piezoelectric strain is generally used to assess the magnitude of the actuator response in a piezoelectric material. In α-quartz homeotypes, it is connected with the piezoelectric stress and the elastic compliance tensor defined under the condition of zero electric field, , according to The calculated elastic compliances of the α-quartz isotypes we considered are listed in Table S3 and are in relatively good agreement with the available experimental values. ,, Our calculated values are also consistent with a previous DFT calculation using the B3LYP hybrid exchange-correlation functional. Calculated piezoelectric strain values are reported in Tables and .…”

“… a The case of α-quartz is given for comparison. Experimental values are in parentheses where available. b Ref . c Ref . d Ref . e Estimation from ref . f Ref . g Ref . h Ref . …”

Highlights on the reversible nonpolar-to-polar P3121–P31 phase transition at low temperature in NaLa(SO4)2·H2O: mechanism and piezoelectric properties

“…Their absolute values are very close and reach 0.139 C m −2 for e 12 . This value is similar to that observed in α-quartz 2 ( e 11 ∼ 0.14–0.17 C m −2 ) and α-quartz-type AlPO 4 1,42 with e 11 = 0.16 C m −2 . However, we are still quite far of the measured values in the langasites such as La 3 Ga 5 SiO 14 with 43 e 11 = 0.44 C m −2 or the theoretical values predicted 19 in BaZnO 2 ( e 11 = 0.72 C m −2 ).…”