We have derived possible domain configurations and macroscopic symmetries that can be induced in the monoclinic Cm phase of PZN-PT crystals by external fields. It appears that electric field can, theoretically, produce 5 different types of coherent configurations (consisting of equivalent domain states of the same free energy in external field(s)) with non-zero average polarization which can be, in principle, switched by electric field. In combination with mechanical stress other 4 types of multidomain structures exhibiting similar properties can be induced. Examples of conceivable polar incoherent engineered structures (containing domain states of different free energy) are also given.
Acknowledgments
This work was done within the project AVOZ1-010-914 of the Academy of Sciences of the Czech Republic. Financial support was provided by the Grant Agency of the Czech Republic under grants 202/04/0992, 202/02/1006 and by Ministry of Education of the Czech Republic under a project MCM242200002.
Notes
a DC's will have minimal free energy if P (1) 3 > P (1) 1 > 0.
b DC's will have minimal free energy if P (1) 1 > P (1) 3 > 0.
c DC's will not have minimal free energy in the specified field.