Appearance of [110] orientated growth layer on (100) face and exposure of (111) faces of cubic bismuth phosphate crystal

• Cubic bismuth phosphate crystal grows in layer by layer model.
• The height of the lowest kinked [010] steps was about one unit cell.
• Growth layers originated from screw dislocation.
• [110] orientated growth layer deduced by atomic deficiency on (100) face.
• (111) faces were in exposure via controlling the growth units complex.

Cubic bismuth phosphate crystals were synthesized by a hydrothermal method at the pH values of 13 and 14. EDS revealed that the ratio of Bi to P was greater than 12. The growth of bismuth phosphate crystal was in a layer by layer model with plenty of concave–convex roughness on the layer surfaces. The layers grew along [010] and [001] directions under lower temperature, while along [110] directions and macroscopic cavities occurred under higher temperature. In addition, layers originated from screw dislocation were observed as well. The growth units would be aggregated together and form complex growth units and improper locations could generate atomic deficiency and further deduce the appearance of [110] orientated growth layer, and ultimately, the (111) faces were exposed. On the other hand, the complexity of the growth units was considered to be beneficial to satisfy the multiple level of growth layers, which was observed by AFM.