Anisotropic magnetic, magnetoresistance, and electrotransport properties ofGdBaCo2O5.5single crystals

Influence of R-ion size on spin state of Co and magnetic properties of RBaCo2O5.50 cobaltites

“…2,5,6,[10][11][12] In this case ͑␦ = 0.5͒, it is well established that oxygen vacancies order forming filled and empty rows of oxygen sites along a in the RO ␦ -planes. Associated with this ordering, intermediate spin ͑IS͒/low spin ͑LS͒ Co 3+ states were found for GdBaCo 2 O 5.50 to be orderly distributed in the structure below T MI ͑IS/high spin ͑HS͒ states above the SS transition at T MI ͒.…”

Crystal structure and structural phase transitions in the GdBaCo2O5.0cobaltite

“…[21][22][23] Moreover, several authors emphasize the importance of the crystal structure to rationalize the orbital and spin states of the transition-metal ions in these materials. 9,20,[23][24][25] Neutron diffraction studies on the Ln = Gd compound may solve the issue, but the considerable neutron absorption coefficient of gadolinium makes them quite difficult if compared to earlier experiments on structurally related compounds. 4 Anyhow, it should be noted that the orthorhombic distortions in the previously mentioned LnBaCo 2 O 5.0 cobaltites are very small, the difference between the a and b parameters being roughly 0.2-0.3% (see Table 1 in Refs.…”

Effect of oxygen content on magnetic properties of layered cobaltites PrBaCo2O5+δ

“…Due to an alternation of CoO 5 square pyramids and CoO 6 octahedra along the b axis leads to its doubling. The CoO 6 octahedra and CoO 5 pyramids in these double perovskites are found to be heavily distorted [9,10] which leads to presence of variety of Co 3+ spin states [11,12] as a function of crystallographic environment and temperature.…”