Physical properties of Na doped CaMnO3

Single phase (Ca1−xNax)MnO3−δ with 0 ≤ x ≤ 0.025 is successfully fabricated using a solid state reaction in air. Electrical resistivity measurements indicate that oxygen vacancies are introduced into the (Ca1−xNax)MnO3−δ at high Na concentration (0.02 ≤ x). The hole carriers may be doped in (Ca0.99Na0.01)MnO3−α which has the lowest resistivity and smallest band gap. The highest signal for the imaginary part of magnetic susceptibility is shown by (Ca0.99Na0.01)MnO3−α at about 115 K. This high signal may be due to magnetic interactions between Mn4+ and Mn6+.