Magnetic properties of “two electron” doped manganites: CaMn1−xWxO3  (0.05≤x≤0.20)

The magnetic properties as well as the electronic transport behaviors of Mn-site electron-doped manganites CaMn1−xWxO3 (0.05≤x≤0.20) have been studied. For low doping level (x=0.05), the system shows the coexistence of multi-magnetic phases which is tunable by the applied magnetic field. For x=0.07, M-T curve shows an obvious phase transition believed to be from paramagnetism (PM) to G-antiferromagnetism (AFM) at around 190 K. With further increase of tungsten concentration (x=0.10,0.12,0.14), besides a transition at Tl∼ 180 K, the system exhibits a peak at Th∼ 350 K. According to the electron diffraction pattern, it is believed that the peak at Th is not a PM to charge ordering (CO) transition but a consequence of orbit ordering. The Jahn-Teller transition induced by the W doping should be responsible for the effect.