Piezoelectric ceramic materials and the main performance parameters

Freedom ε dielectric constant T33 (free permittivity)
In the dielectric constant strain zero (or) of dielectric constant, the unit for ferrari/meters.
Relative permittivity ε Tr3 (relative permittivity)
ε dielectric constant T33 and vacuum ε dielectric constant of 0 ε ratio, ε T33 / ε Tr3 = 0, it is one of the non-dimensional quantities.
Dielectric (loss) dielectric loss
The dielectric in electric power, due process and leakage of relaxation polarization reasons such as conductivity in the dielectric loss of energy within.
Dissipation factor of loss tangent delta (tg Angle)
The ideal in the sinusoidal alternating electric dielectric under the current flows than voltage phase, but in the 1990s 0 ahead of piezoelectric ceramic sample for energy losses, the current advance of ψ phase, it is less than $900 YuJiao delta (= 9) delta + ψ called loss Angle, it is one of the non-dimensional quantities, people usually use dissipation factor tg delta to the size of the dielectric loss, it expressed the dielectric loss of active power (power) P and reactive power Q. Namely:

Electricity quality factor Qe (in) on electrical
Electricity quality factor value equal to sample the dissipation factor value with Qe countdown, said, it is a the non-dimensional quantities. If use parallel equivalent circuit of alternating electric field that piezoelectric ceramic sample, Qe = 1 / tg delta = ω CR
Mechanical quality factor in mechanical (Qm) quanlity
Piezoelectric resonators in resonance with the mechanical energy saving in a cycle of energy loss than called mechanical quality factor. It is the relation with the vibrator parameters for:

Poisson's ratio poissons (from)
Poisson's ratio refers to the solid in stress under the action of transverse and longitudinal contraction relative relative elongation ratio, is a variation of the non-dimensional with delta, said:
The delta = - S 12 / S11
Fs series resonant frequency (some) resonance better
Piezoelectric resonators equivalent circuit series branch resonant frequency called the resonant frequency, in f series, said that "s

Parallel resonant frequency fp method, resonance that some)
Piezoelectric resonators equivalent circuits of parallel branch of parallel resonant frequency called the resonant frequency, the f p says, namely f p =
The resonant frequency (fr) resonance some
Make piezoelectric resonators electricity for a pair of zero frequency low frequency called a resonant frequency, the f r said.
The resonant frequency antiresonance fa (some)
Make piezoelectric resonators electricity for a pair of zero frequency a higher frequency called the resonant frequency, the f akel says.
Maximum admittance frequency FM (some) maximum admittance
Piezoelectric resonators admittance of maximum frequency called the biggest admittance of frequency, at least, is also called impedance frequency with minimal impedance, f. m. said.
The minimum 12.7mm fn (minimum frequency admittance admittance some)
Piezoelectric resonators admittance of the frequency at least admittance frequency, called the largest vibrator, also called impedance greatest impedance frequency, the f n.
A frequency (some) contrasted
Given a vibration mode in the lowest frequency resonant frequency called pitch, usually as a frequency.
The sound frequency (some) contrasted
Given a vibration mode frequency resonant frequency called outside the sound frequency.
Temperature stability (temperature batch-convert)
Temperature stability piezoelectric properties refers to changes with temperature.
In a certain temperature, the temperature change 1 ° c, a certain frequency and the temperature change of the numerical values of the frequency, the temperature coefficient TKf called frequency.
TKf =

In addition, usually with maximum drift to represent a relative parameters of temperature stability.
Temperature is the greatest relative frequency shift = train f s (are) / f s largest temperature (25 ° c),
Negative temperature maximum relative frequency shift = train f s (negative maximum temperature (s) / f of 25 degrees Celsius)
Electromechanical COUPLING COEFFICIENT (ELECTRO MECHANICAL COUPLING COEFFICIENT)
Electromechanical coupling coefficient K is elastic raised electric energy density interaction with elastic storage V122 square to density and dielectric can density V2 V1 the square root of the product is.

Piezoelectric ceramics used the following five basic coupling coefficient

A planar electromechanical coupling coefficient KP mohan, thin wafer (along the direction and the thickness of polarization, radial vibration excitation telescopic timing parameters of electrical coupling effect).
B, transverse electromechanical coupling coefficient K31 (reflects the thickness of the slender and electric polarization direction along the length of incentive, mechanical &electrical coupling vibration of adjustable parameters of the effect.
C, longitudinal electromechanical coupling coefficient K33 (reflect the length direction of fine bar and the incentive, polarization coupling vibration of mechanical length is adjustable parameters of the effect.
D, thickness telescopic electromechanical coupling coefficient reflects the thickness thin KT (polarization direction and the incentive and thickness of mechanical vibration direction adjustable parameters of the effect.
E, thickness shear electromechanical coupling coefficient reflects the rectangular plate K15 (length direction along the direction of electric polarization, perpendicular to the direction of polarization, thickness shear vibration parameters of electrical coupling effect of time).

D (PIEZOE piezoelectric strain constants