Table II.

Comparison of piezoelectric properties achieved from different approaches for several lead-free materials.

Materials	d33 (pC/N)	$d_{33}^{\ast }(\text{meter})$(pC/N)	$d_{33}^{\ast \ast }$ (pm/V)	Loss (%)	Extrinsic contribution(%)(at 1kV/cm)
KNNTL:Mn single crystala	545±20	630±30	870±30	0.7±0.1	13.3
KNNTL-1 single crystalb	354	420	672	2	21.6
KNNTL-2 single crystalc	255	280	470	1	-
KNNT single crystald	162	200	305	0.4	-
KNNTL0.2 ceramicse	174	195	308	<10	-
NBBT95/5 single crystalf	360	420	-	1.1	9.61

^aThis work,

^bRef.13,

^cRef.7,

^dRef.12,

^eRef.8,

^fRef.11