HoFeTi2O7: Synthesis, Peculiarities of the Crystal Structure, and Magnetic Properties

Polycrystalline samples of HoFeTi2O7 were obtained by solid-phase synthesis and investigated using X-ray diffraction, gamma resonance, and SQUID measurements. Characteristics of the structural properties are presented, which give an evidence of the distribution of iron atoms among nonequivalent crystallographic positions and of the nonuniform populating of positions mixed with titanium by the iron atoms. Spin disorder caused by mixing of magnetic and nonmagnetic ions, spatial nonuniformity of the interactions defining the magnetic structure in the crystal lead to formation of concurrent magnetic exchange interactions between the nearest neighbors, frustration of magnetic couplings, and loss of the long-range magnetic ordering. The temperature dependence of the magnetic susceptibility at low temperatures was shown to have some peculiarities typical of the magnetic state of spin glass.