ADP-NH(4)Sal hybrid crystals are grown from aqueous solutions. The influence of the acidity of the mixed solution on the conditions of co-crystallization of the components is studied. The spectral and scintillation characteristics are determined. Co-crystallization of ammonium salicylate (NH(4)Sal) and ammonium dihydrogen phosphate (ADP. NH(4)H(2)PO(4)) is shown to be feasible, the structure of the doping addition being defined by the solution pH. In basic and weak acidic media the hybrid crystals ADP:NH(4)Sal are formed in which salicylate anions are located in the interplanar space between the {110}-type planes in the lattice of ADP. The luminescence spectra contain an emission band maximum with lambda(max)=360 nm. In acidic solutions there are ADP:HSal crystals in which salicylic acid molecules captured by the growth macrosteps are located in the interplanar space of the prismatic {100} and pyramidal {101} growth sectors. The luminescence band undergoes bathochromic shift to lambda(max)=400 nm. The sensitivity of ADP:NH(4)Sal scintillation crystals to fast neutrons depends on the concentration of ammonium salicylate in ADP matrix. The highest neutron sensitivity is characteristic of the co-doped ADP:NH(4)Sal/Tl scintillation crystals. (C) 2011 Elsevier B.V. All rights reserved.