Oxygen Gettering Effect During the Reactive Evaporation of Manganese Oxide Films

Abstract

Manganese oxide films for lithium secondary batteries were prepared using a reactive evaporation method. Mn was evaporated from a molybdenum boat by resistive heating and deposited on a glass slide under oxygen atmosphere. These films were examined with x-ray photoelectron spectroscopy (XPS) and x-ray diffraction. The Mn oxide films with a wide valency of Mn were prepared in this study. A rapid change of the back pressure was found as the deposition of Mn was started. This implies that Mn atoms start to react with O2. This means that in situ detection of reactive evaporation process can be utilized.

Ultraviolet-assisted pulsed laser deposition of La0.7Ca0.3MnO3 thin films with improved oxygen content, crystallinity and magnetoresistive properties

“…In order to obtain a good fitting of the experimental data four peaks were necessarily included. [11][12][13][14] Thus our XPS results show that the LCMO films grown in the prescence of UV is definitely superior to the LCMO films grown without UV in terms of Mn 4ϩ /Mn 3ϩ ratio and oxygen content. First it is worth mentioning that the ratio of Mn 4ϩ /Mn 3ϩ is higher in the LCMO film grown in the presence of UV ͑ϳ 80%͒ than in LCMO film grown without UV ͑ϳ 70%͒.…”

Investigation of deposition condition of LiMn₂O₄ films prepared by RF magnetron sputtering

“…These weak points would be resolved by using Li secondary batteries. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The Li secondary battery has a high energetic density and a high voltage that exceeds the electrolysis voltage of water. So non-water electrolyte should be used.…”

“…The use of LiMn 2 O 4 instead of LiCoO 2 has been proposed. [8][9][10][11][12][13][14][15][16][17][18][19][20] If LiMn 2 O 4 is used, the problems in the resource and the toxicity could be cleared, and we can make the secondary batteries with lower price than those of LiCoO 2 electrodes.…”

“…[8][9][10][11][12][13][14][15][16][17][18] This is because Mn 3 O 4 has the spinel structure, this structure can accept Li ions easily, and has a longer lifetime as compared with other electrodes. [1][2][3][4][5][6][7] However, when the Mn 3 O 4 thin films were used as a positive-electrode, and the Li thin films were used as a negative-electrode, we couldn't measure the battery characteristics.…”

Preparation of LiMn₂O₄ Films by RF Magnetron Sputtering Method

“…[10][11][12][13][14][15][16][17][18][19][20][21][22][23] In our early studies, Mn 3 O 4 films have been successfully prepared. [15][16][17][18][19][20][21][22][23] But, unfortunately, charge-discharge curves could not be measured. It seems that this is due to the deficiency of Li ions moving between positive and negative electrodes during charge and discharge process.…”