Fabrication of M³⁺-Substituted and M³⁺/V⁵⁺-Cosubstituted Bismuth Titanate Thin Films [M=lanthanoid] by Chemical Solution Deposition Technique

Preparation and Properties of Bi4 ? xNdxTi3O12 Thin Films by Chemical Solution Deposition

“…Among these films, BNT [x = 0.75] thin films showed the highest remanent polarization (P r ) of 22 µC/cm 2 and a relatively low coercive electric field (E c ) of 69 kV/cm at an applied voltage of 5 V. This large ferroelectricity of current BNT films may be attributable to the change in crystal orientation from the random orientation having 00l diffractions with high intensities to the random orientation with a strong 117 reflection, and to the tilting of TiO 8− 6 octahedra derived from the substitution of Nd 3+ which has a smaller ionic radius than those of Bi 3+ [7][8][9][10]. Uchida et al achieved the P r of 24 µC/cm 2 (E c > 100 kV/cm) for 750 • C annealed BNT films prepared by the CSD [6]. In this study, the comparable P r with lower E c is achieved at 50 • C lower temperature (700 • C) and at lower applied voltages.…”

“…Recently, the improvement of electrical properties of BIT thin films by rare-earth ion doping has been reported by several researchers [1][2][3][4][5][6][7][8][9][10]. Among them, Bi 4−x Nd x Ti 3 O 12 (BNT) has been receiving much attention due to its larger ferroelectricity than that of the other rare-earth ion doped BIT [5][6][7][8][9][10]. Therefore, the optimization of the amount of neodymium (Nd) substitution into BIT films is strongly required for the fabrication of BNT films with excellent ferroelectricity.…”

Structure dependence of the ferroelectric properties of Bi3.25Ln0.75Ti3O12 (Ln=La, Nd, Sm, Dy) ceramics

“…BLSF ceramics have the general formula of (Bi 2 O 2 ) 2+ (A m−1 B m O 3m+1 ) 2− , where A=Bi, Pb, Ba, Sr, La, Ca, Na, K; B=Ti, Nb, Ta, W, Mo, Fe, Co, Cr, and m is the number of BO 6 octahedrals in the pseudoperovskite block (m=2, 3, 4, 5) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Bi 4 Ti 3 O 12 (BIT) is one of the more extensively studied materials among the BLSF family due to its large spontaneous polarization along the a-axis (approximately 50 μC/cm 2 ), [4] low processing temperature, high Curie temperature, and lead-free composition.…”

“…Recently, it has been reported that the oxygen-vacancy migration in BIT ceramics with the substitution of rare-earth ions has a significant effect on its electric properties. Rare-earth ion modified BIT (Bi 4−x Ln x Ti 3 O 12 ; Ln=La, Nd, Sm) films were reported to have relatively high ferroelectricity and good fatigue-free characteristics [7][8][9]. The ferroelectric property of the Bi 4−x La x Ti 3 O 12 ceramics differs according to the value of x [3,10].…”

Conduction mechanism of grain oriented Bi3.15Nd0.85Ti3O12 ceramics fabricated by a hot-forging method

“…It is commonly known that proper element doping (at the Bi-site with Sm, La, Nd or Ti-site with V, Ta, Nb, W) in the perovskite-type unit of Bi 4 Ti 3 O 12 can effectively enhance piezoelectric and ferroelectric properties [6]. Recently, lanthanum and neodymium-substituted BTO were reported to have a relatively large remanent polarization (2P r ∼24 μC/cm 2 ).…”