Valence states and dielectric properties of fine-grained BaTiO3 ceramics co-doped with double valence-variable europium and chromium

Dielectric and photoluminescence properties of fine-grained BaTiO3 ceramics co-doped with amphoteric Sm and valence-variable Cr

“…It is based on the following evidences: Ba-vacancy related g ¼ 1.974 signal generally shows a very narrow linewidth. [36][37][38] Moreover this signal corresponds very well to measure results of Müller and Schwartz, 26,29 their Cr 3+ causing a frequency-independent line width of 240 G. The intensity of this signal is decreased with increasing x for BSTC and BSTC1.…”

Stable Tunable Luminescence of Hetero-valent Eu Ion Activated Ba2InTaO6 Phosphors Synthesized by Defect-Induced Self-Reduction in the Molten-Salt Method

“…The HR-XPS spectrum of Ba is composed of two main peaks at 779.3 and 794.6 eV in Figure b, corresponding to the Ba 3d 5/2 and 3d 3/2 , respectively. , In Figure c, the two strong peaks at around 444.1 and 451.7 eV correspond to In 3d 5/2 and In 3d 3/2 , which are due to the In 3+ . , The peaks that were observed at 25.4 and 27.4 eV in Figure d can be assigned to the binding energies of Ta 4f 7/2 and 4f 5/2 , respectively. , In the high-resolution XPS spectra of Eu 3d, the characteristic peaks of Eu 3+ and Eu 2+ were observed. The four peaks at 1134.3, 1163.2, 1123.7, and 1152.9 eV were obtained by XPSPEAK4.1 software fitting, corresponding to the binding energy of 3d 5/2 and 3d 3/2 of Eu 3+ and Eu 2+ , ,, and the ratio of the peak area of Eu 3+ /Eu 2+ was 2:1. The peak of O 1s shows a high degree of asymmetry from Figure f, and two peaks of 529.6 and 534.3 eV can be obtained by fitting.…”

“…The radius of the Ba 2+ ion is 1.61 Å (CN = 12), that of the In 3+ ion is 0.80 Å (CN = 6), that of the Ta 5+ ion is 0.64 Å (CN = 6), that of the Eu 3+ ion is 0.95 Å (CN = 6), and that of the Eu 2+ ion is 1.45 Å (CN = 12). 22,23 According to the principle of charge balance and radius similarity, it can be speculated that both Eu 3+ and Eu 2+ ions can replace In 3+ or Ba 2+ ions. Since the proportion of synthetic raw materials is controlled according to the substitution of Eu 2 O 3 for In 3 O 3 , the In 3+ position should be preferentially occupied by Eu 3+/2+ .…”

“…27,29 In the high-resolution XPS spectra of Eu 3d, the characteristic peaks of Eu 3+ and Eu 2+ were observed. The four peaks at 1134.3, 1163.2, 1123.7, and 1152.9 eV were obtained by XPSPEAK4.1 software fitting, corresponding to the binding energy of 3d 5/2 and 3d 3/2 of Eu 3+ and Eu 2+ , 23,30,31 and the ratio of the peak area of Eu 3+ /Eu 2+ was 2:1. The peak of O 1s shows a high degree of asymmetry from Figure 5f, and two peaks of 529.6 and 534.3 eV can be obtained by fitting.…”

Optimization of Sintering Conditions to Enhance the Dielectric Performance of Gd3+ and Ho3+ Codoped BaTiO3 Ceramics

“…( a ) t d = 1 h, ( b ) t d = 3 h, ( c ) t d = 6 h, ( d ) t d = 12 h. The frequency dependence of the dielectric constant ( ε′ ) and dielectric loss (tan δ ) was measured at room temperature for BGTH7 ceramics sintered at T s = 1400 °C for different t d ( e ) and ( f ). ( g ) The dielectric properties of this work are compared with those of previously reported BaTiO 3 -based dielectric ceramics with X7U specifications [ 2 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ].…”