Electric-field-induced structural changes inKH2PO4at room temperature and at 167 K

Effect of strain in crystal on the forbidden reflections in the resonant diffraction of synchrotron radiation

“…In reality, the excitation of acoustic vibrations in a piezoelectric crystal induces an electric field, which changes not only the unit cell parameters but also the atomic coor dinates in the unit cell. Van Reeuwijk et al [30] used the nonresonant diffraction of synchrotron radiation to determine the atomic coordinates in potassium dihydrogen phosphate crystal under excitation of structural changes after applying an electric field with Table 1 in [30]). These data were used to calculate the effect of uniform strain on the properties of the forbidden 002 reflection.…”

“…The crystal structure of potassium dihydrogen phosphate was studied by X ray diffraction and neu tron diffraction [26][27][28][29][30][31][32][33][34][35][36][37][38]. At room temperature the unit cell sizes are a = 7.4521(1) and c = 6.974(2) Å.…”

Time-resolved x-ray diffraction study of the relaxation process of electric-field-induced strain in KD2PO4

“…One can think of intensity measurements where intensity differences between two quasi-static states of an external electric field are to be determined using the modulationdemodulation technique. 7,13 The strain relaxation should take place on a time scale much shorter than the modulation period of the electric field. The rocking curves of the two quasistatic states can be completely separated when a sufficiently strong electric field is applied.…”

“…[1][2][3][4][5][6] Recently, we performed x-ray diffraction experiments to determine the electric-field-induced structural deformations in KH 2 PO 4 and KD 2 PO 4 ͑DKDP͒ crystals. 7 As the crystals are piezoelectric, an external electric field deforms the unit cell. This induced strain, the so-called external strain, is accompanied by small displacements of the atoms inside the unit cell, the so-called internal strain.…”

Theory of related to shear strain u6 physical properties of ferroelectrics and antiferroelectrics of the KH2PO4 family

“…The obtained theoretical results are compared with the corresponding experimental data for KH 2 PO 4 and NH 4 H 2 PO 4 crystals. The theory parameters found herein will allow to determine within the given model the electric-field-induced structural change which is connected with the deformation u 6 in these crystals [23].…”