[1] Univ Fed Uberlandia, Grp Ferroeletr & Mat Multifuncionais, Inst Fis, Uberlandia, Brazil
[2] Univ Habana San Lazaro & L, Fac Fisica?, Inst Ciencia & Tecnol Mat, Havana, Cuba
[3] Univ Texas San Antonio, Coll Engn, Dept Elect & Comp Engn, Multifunct Elect Mat & Devices Res Lab, San Antonio, TX USA