TY - JOUR
T1 - Crystal growth features and properties of layered rare earth and barium cobaltates
AU - Bychkov, G. L.
AU - Shiryaev, S. V.
AU - Soldatov, A. G.
AU - Shestak, A. S.
AU - Barilo, S. N.
AU - Sheptyakov, D. V.
AU - Conder, K.
AU - Pomjakushina, E.
AU - Podlesnyak, A.
AU - Furrer, A.
AU - Bruetsch, R.
PY - 2005/4
Y1 - 2005/4
N2 - High quality single crystals of LnBaCo2O5+δ (0 < δ < 1) (Ln = Pr, Eu, Gd, Tb, Dy) with rectangular shape and average dimensions 5 mm × 5 mm × 1 mm were grown for the first time from overstoichiometric flux melt. The data on the primary crystallization field of most cobaltate phases, which appear in parts of corresponding Gibbs triangles in the range 1373 - 1523 K are discussed. Bulk single crystals of new phases HoBaCo4O7 up to 300 mm3, YBaCo 4O7 and TbBaCo4O7 up to 10 mm 3 in volume were grown first. A solution of these compounds structure has been found in the space group P63mc. For the Ln = Pr, Gd, Sm, Tb, Dy, Ho based systems under the liquidus line there are several other new cobaltate phases of both perovskite, and hexagonal crystal structure. Stability of the double perovskite phase and temperature of the antiferromagnetic - ferromagnetic phase transition in relation to the radius of rare earth ions are compared. The data on the exact analysis of chemical composition, including EDX and iodometric titration, as well as results on magnetic susceptibility of EuBaCo1-xAlxO5+δ (0 < x < 0.3) are discussed.
AB - High quality single crystals of LnBaCo2O5+δ (0 < δ < 1) (Ln = Pr, Eu, Gd, Tb, Dy) with rectangular shape and average dimensions 5 mm × 5 mm × 1 mm were grown for the first time from overstoichiometric flux melt. The data on the primary crystallization field of most cobaltate phases, which appear in parts of corresponding Gibbs triangles in the range 1373 - 1523 K are discussed. Bulk single crystals of new phases HoBaCo4O7 up to 300 mm3, YBaCo 4O7 and TbBaCo4O7 up to 10 mm 3 in volume were grown first. A solution of these compounds structure has been found in the space group P63mc. For the Ln = Pr, Gd, Sm, Tb, Dy, Ho based systems under the liquidus line there are several other new cobaltate phases of both perovskite, and hexagonal crystal structure. Stability of the double perovskite phase and temperature of the antiferromagnetic - ferromagnetic phase transition in relation to the radius of rare earth ions are compared. The data on the exact analysis of chemical composition, including EDX and iodometric titration, as well as results on magnetic susceptibility of EuBaCo1-xAlxO5+δ (0 < x < 0.3) are discussed.
KW - Cobaltates
KW - Magnetic transition
KW - Phase diagram
KW - Phase transition
KW - Primary crystallization field
KW - Single crystal growth
UR - http://www.scopus.com/inward/record.url?scp=25444482625&partnerID=8YFLogxK
U2 - 10.1002/crat.200410356
DO - 10.1002/crat.200410356
M3 - Article
AN - SCOPUS:25444482625
SN - 0232-1300
VL - 40
SP - 395
EP - 399
JO - Crystal Research and Technology
JF - Crystal Research and Technology
IS - 4-5
ER -