Structure of KD 2 PO 4 Embedded in a Porous Glass

The temperature evolution of the crystal structure of KD2PO4 (DKDP) embedded in a porous glass with 7 nm pore diameter has been studied by neutron diffraction in temperature interval 90 K-308 K. It is shown that confined DKDP forms interconnected clusters with characteristic size of 18(0.5) nm. The structure of this nanocomposite material is found to be monoclinic and corresponds to the space group P2(1). The lattice parameters and characteristic cluster size are temperature independent and do not reveal any peculiarities in the vicinity of expected ferroelectric phase transition of 223 K.