Metastable T′-phase in bulk La2−xLnxCuO4 (Ln = Sm and Y)

We prepared the metastable T′-phase La2−xLnxCuO4 (Ln = Sm and Y) cuprates by a coprecipitation technology, which cannot be acquired by conventional solid-state reaction. The selective stabilization of T′- and T-phase was studied via altering synthesis temperature and pressure. The structural phase diagram for T- and T′-phase is obtained in La2−xLnxCuO4 system. All these samples show semiconducting behavior, and no superconductivity was observed down to 2 K even after reduction. Magnetic measurement shows a Curie-Weiss-like paramagnetic behavior.