| A review on progress in crystal growth and study of layered cobaltites is presented. Single crystals of the LnBaCo2O5+δ (Ln = Pr, Sm, Eu, Gd, Tb, Dy, Tb0.9Dy0.1) family with the giant magnetoresistance (MR) effect were grown by the flux technique. Co-crystallization with the geometrically frustrated LnBaCo4O7 phase was registered in a wide range of temperature. The details of structure of the as-grown and detwinned single crystals and their characterization by magnetic susceptibility, magnetoresistance, X-ray and neutron diffraction are discussed. A comparative study of the twinned and twins free EuBaCo2O5+δ single crystals reveals a positive magnetoresistance effect ∼ 500% at low temperature. |
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