Electrical Properties of Manganese Dioxide and Manganese Sesquioxide

Abstract

Measurements of electrical properties of MnO2 and Mn2O3 were carried out on material obtained by pyrolysis of normalMnfalse(NO3)2 . From resistivity data, it is proposed that the conduction process is due to oxygen forming a donor level at 0.044 eV. In Mn2O3 , oxygen vacancies might be acting as an acceptor level with an activation energy of 0.30 eV. Resistivity measurements were used to establish the MnO2‐Mn2O3 transition temperature at 545°C. The Hall mobility of MnO2 was measured at 25°C. For resistivities of 0.1–100 ohm‐cm, the mobility depends on the resistivity. This was taken as an indication that impurity scattering is the dominating process in this region. The voltage‐current characteristic was measured for samples from 0.1 to 105 ohm‐cm. The material showed ohmic behavior for fields from 10 mV/cm to 100 V/cm. The Seebeck coefficient was investigated over the temperature range 25°‐125°C. A response of 0.6 mV/°C was found in high‐resistivity n‐type MnO2 , and 0.37 mV/°C in normalp‐type Mn2O3 .

Alternating‐Current Properties of Organic Semiconductor Solid Capacitor

“…For the OSS-A, the slope of the ESR* was higher than 45 ~ and the ESR* approached that of the dried anodized capacitor at 6 kHz. The specific resistivity of the organic semiconductor film was about 1 ~-cm experimentally, and published data for MnO2 range from 0.1 to l0 s ~-cm (10). The comparative studies on the representative capacitors furthermore indicate that the counterelectrode has a general adverse effect of presenting a plateau at intermediate frequencies (9).…”

The Initial Oxidation of Manganous Oxide—Application of the Mott-Hauffe-Ilschner Mechanism

“…In the present investigation, the film grown on the surface of MnO is Mn2O3 which has the crystal structure of scandium oxide type and is confirmed to be a p-type semi-conductor (12) being capable to accommodate the excess oxygen ions at interstitial sites. Therefore, it is reasonable to assume that the range of cubic law x3 =kct appears next to the inverse logarithmic range, where kc is proportional to exp(-W/ kT).…”

Temperature effect on the electrical properties of pyrolytic MnO2 thin films prepared from Mn(C2H3O2)2·4H2O

“…Calculated values of f b are given in Table 3. The value of f b by the early work is of the order of 0.044 eV [21].…”

“…(1) are also tabulated in Table 2. The donor levels are shallow and are mainly due to the native defects, such as interstitial manganese and oxygen vacancies [21]. Considering a hydrogenic model for the impurities, the density of states effective mass m à e can be calculated in such a material using the relation [20] …”

“…The donor density (N d ) is greater than the carrier concentration (n) for MnO 2 samples, which is the characteristic for an uncompensated semiconductor [17,18]. In undoped films the oxygen vacancies and the interstitial chlorine ions (incorporated in the film from the working solution) may act as the major sources of donors [17,18,21]. Besides, interstitial Mn could be activated too.…”