Manganese oxides over the last few years have experienced a considerable increase in research interests due to their rich and complex phase diagrams, that are a result of the flexibility of the manganese ions oxidations states. The compounds in the Ca-Mn-O system provide an excellent platform, where theoretically predicted multiferroic behavior could exist. Many manganese oxides have already been thoroughly investigated; however, a potential candidate CaMn₂O₄ is still not well understood to date.

Polycrystalline CaMn₂O₄ samples were synthesized and annealed in oxygen and argon flows respectively to further explore the effect of oxygen deficiencies on the physical properties. From temperature dependent dc magnetization and heat capacity measurements, the previously reported antiferromagnetic ordering near 220 K was observed for both samples. However, a spontaneous polarization (P_S) was observed near 253 K for only the oxygen annealed sample without applied magnetic field, while no P_S was observed for the argon annealed sample. In addition, the dielectric and loss measurements revealed anomalies above 260 K with the time and magnetic field dependent phenomena in both samples. Detailed measurements for both samples are ongoing to gain greater insight into this complex system.