|Crystal growth and characterization of (DyxLa1–x)2Ti2O7 crystals|
JACKO, R., MIHALIK, M., MIHALIK Jr., M., ZENTKOVÁ, M., ROUPCOVÁ, P.
vol. 58 (2020), no. 1, pp. 59 - 70
LaTiO3.5 crystals were grown by optical floating zone technique in air, O2 or Ar. Crystal structure varies between orthorhombic Pna21 (air, O2) and monoclinic P21 (Ar). Crystals are transparent (air, O2) or opaque (Ar) with amber or black colour. Magnetization resembles properties of LaTiO3.5. (DyxLa1–x)2Ti2O7 crystals were grown in O2. The solubility of dopant (La or Dy) in the parent compound is limited. Two phases with Pna21 and Fd¯3m structure coexist in the range from x = 0.32 to 0.68. The a-axis of Pna21 is intact by substitution of La3+ by Dy3+; both b- and c-axis decreases. The a-axis of Fd¯3m increases with substitution of Dy3+ by La3+ and the spin freezing temperature Tf shifts to higher temperature. Either of new magnetic phase (Pna21 structure) or dynamical behaviour of spins in Fd¯3m phase exists below x = 0.68 in the range between transition to ‘spin ice’ state Ti and Tf.
optical floating zone, single crystals, crystal structure, ferroelectrics, spin ice
Full text (1570 KB)