Inner differentiation of growth sectors induced by the interaction between dislocations and sector boundaries in KH2PO4 crystals

Shift of the transition temperature in the growth bands of potassium dihydrogen phosphate monitored by electron paramagnetic resonance

“…The differences consist of slightly lower values for the Bq = D / 3 and BZ = E spin-Hamiltonian parameters, as well as for the ratio 3E/D; moreover, the Z principal axis, defined as the axis exhibiting maximum splitting of the spectrum, is exchanged with the Y axis for Cr3+ in the bulk sample [l, 21. These differences have been interpreted as being a consequence of a slight increase in the lattice parameters in the growth-band samples (GB samples) with respect to the regular samples (R samples). This explanation is supported by the measurement of the c parameter of samples taken from the growth-band region using synchrotron radiation plane-wave reflection topography [3], which shows a relative lattice parameter difference dc/c of around 2 x lo-' with respect to regular (inner) samples. Although the a and b parameters have not been measured in [ 3 ] ,…”

“…This explanation is supported by the measurement of the c parameter of samples taken from the growth-band region using synchrotron radiation plane-wave reflection topography [3], which shows a relative lattice parameter difference dc/c of around 2 x lo-' with respect to regular (inner) samples. Although the a and b parameters have not been measured in [ 3 ] ,…”

“…( 5 ) (6) and, taking increments, we get Substituting in the values for the lattice parameters [6] a = 7.4529 A, c = 6.974 A and the increment of the c parameter given in [3], dc/c = 2 X 10-' for the GB samples, weobtainarelativeincrementfor theaparameteraala = 9 X whichis considerably higher than that along the c axis, and which is in agreement with the interpretation of the EPR spectra measured at room temperature given in [ 11.…”