Figure 3
From: First experimental evidence of the piezoelectric nature of struvite
(a) Piezoelectric signal at 293 K, with characteristic dependence of admittance |Y| near piezoelectric resonance fr and antiresonance fa. The red line represents fit to experimental data based on the model described in Ref. 30. The inset represents changes of phase shift θ in the relationship Y = |Y| e iθ. (b) The temperature evolution of piezoelectric resonances shows a shift of resonances towards lower frequencies with increasing temperature. All dependencies in Figs. a and b have been obtained for the strength of the measuring field amounting to 0.035 V/cm. c) d32 piezoelectric coefficient in a function of temperature in low temperature range. Standard deviation for each measuring point is shown. The dashed black line is the linear fit to the measurement points showing a weak increase in d32 with temperature.
