In our case, since the solution prepared is maintained at a high pH= 9, the
different planes will have different OH− concentration, which will with high energy, i.e. (1 1 0) plane (since growth is along direction [0 0 2]) will exhibit increase inOH− concentration, and this possibly
restricts the movement of Ca2+ and PO4 3− in the formed nucleus in one particular direction, i.e. [0 0 2]. In this condition,OH− templates the nucleation process where free Ca2+ and PO4
3− react with OH− in uniaxial direction (planes with less OH− concentration), nucleating into HA nanorods. This is schematically represented in Fig. 5