Grain size and grain boundary-related effects on the properties of nanocrystalline barium titanate ceramics

Domain Wall Displacement is the Origin of Superior Permittivity and Piezoelectricity in BaTiO3 at Intermediate Grain Sizes

“…At a grain size of ~3.5 μm (Figure 4(c)), significant 90 domain wall motion is also observed, though to a lesser extent than at a grain size of ~2 µm. 13 Summarizing these observations from Figure 4, it is clear that significant 90° domain wall motion occurs during the bipolar high-field cycling at grain sizes of ~2 and ~3.5 µm whereas less 90° domain wall motion occurs at the smaller grain size of 0.3 µm. Thus, 90 domain wall motion is seen to increase with increasing grain size from 0.3 to ~2 µm, then decrease slightly with a further increase in the grain size to ~3.5 µm.…”

“…In polycrystalline ferroelectrics, size effects are chiefly evident in materials properties such as the relative dielectric permittivity ( r ) and piezoelectric coefficients (e.g., d 33 and d 31 ). For polycrystalline barium titanate (BaTiO 3 ), the effect of grain size on the relative permittivity has been extensively reported over the past decades [3,4,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and is of particular relevance to the continuous size reduction of BaTiO 3 capacitors. Within the grain size range of 1-10 µm, it is now widely accepted that  r of polycrystalline BaTiO 3 increases with decreasing grain size, reaching a value of 5000, or higher, as the grain size approaches 1 µm.…”

Effect of grain size on the dielectric properties of Lanthanumdoped PbTiO3 perovskite ceramics

“…Buscaglia et al [8], observed a similar behavior when they studied BaTiO 3 nanostructured ceramics prepared by a spark plasma sintering technique (SPS), they observed a shift in the phase transition temperature (Curie temperature) a shift towards lower values by decreasing the grain size was smaller than 100 nm.…”

Additive-Assisted Aqueous Synthesis of BaTiO3 Nanopowders

“…Barium hydroxide, Ba(OH) 2 3 8H 2 O (Merck, 98% purity), and titanium n-butoxide, Ti(n-OBu) 4 (Aldrich, 97% purity), were used as barium and titanium precursors, respectively. Poly(acrylic acid) (PAA, Aldrich, M w = 2000), poly(vinylpyrrolidone), (PVP, Acros Organics, M w =8000), D-fructose (Fru, Acros Organics, 99% purity), hydroxypropylmethylcellulose (HPMC 100, Sigma), and sodium dodecylsulfate (SDS, Aldrich, p.a.)…”

“…Additive concentrations used were 0.4 and 5 g/L for [low] and [high] concentration, respectively. The mixture of barium hydroxide and additives was cooled down to room temperature and 5.7 mL of Ti(n-OBu) 4 was added under vigorous stirring. A rapid formation of a white precipitate of hydrous titanium oxide in alkaline solution was noticed.…”