[1] Pukyong Natl Univ, Dept Phys, Pusan 608737, South Korea
[2] Kyoto Sangyo Univ, Fac Engn, Kyoto 6038555, Japan
[3] Natl Inst Mat Sci, Optron Mat Ctr, Tsukuba, Ibaraki 3050044, Japan
[4] Univ Verona, Lab Solid State Chem, Dept Biotechnol, I-37134 Verona, Italy
[5] UdR Verona, INSTM, I-37134 Verona, Italy
[6] Natl Inst Mat Phys, Bucharest 77125, Romania