Structural and magnetic characterizations of undoped and K-doped NdMnO3 single crystals synthesized by sol–gel route: A comparative study

Stoichiometric undoped and 15% K-doped NdMnO3 perovskite rare earth manganate tiny single crystals are synthesized by sol–gel route within a short duration and at lower sintering temperature. Structural characterizations of NdMnO3 and Nd0.85K0.15MnO3 compounds by the Rietveld structure refinement method revealed that undoped and K-doped NdMnO3 belong to monoclinic and orthorhombic structure respectively. HRTEM images substantiate the formation of tiny single crystals of these compounds. Magnetic studies using SQUID magnetometer reveal that NdMnO3is anti-ferromagnetic with Néel temperature 67.2 K and Nd0.85 K0.15MnO3 is ferromagnetic with Curie temperature 99.6 K. The ac susceptibility measurements depict a Mn-spin ordering below 77 K in NdMnO3 and a spin glass type behavior at low temperature in Nd0.85 K0.15MnO3.