Effect of grain size on the resistivity of polycrystalline material

Highly c-axis oriented AlN film grown by unbalanced magnetron reactive sputtering and its electrical properties

“…6 (c) shows the typical I-V characteristics of AlN films (whose thicknesses are all approximately 700 nm) measured at room temperature with the applied voltage from -10 V to 10 V. The leakage current density of AlN-0 at 5 V bias voltage is about M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 12 1×10 -6 A/cm 2 , which is one order of magnitude higher than that of the AlN-1.0 (>1×10 -7 A/cm 2 ) measured under the same condition. The result indicates that the additional magnetic field can improve the insulating property of AlN films, and this must be related to the improvement in the quality of the films in UBMS [1,[30][31][32].…”

“…6 (a) Moreover, the dielectric constant of the AlN-1.0 remains relatively stable with the increase of frequency, while the AlN-0 exhibits sharp decline. Some researches showed that large grain sizes, low surface roughness, compact and uniform structures are associated with large dielectric constants [30][31][32]. Other researches indicated that the dielectric constant is dependent strongly on the orientation [33][34][35] and for AlN films, the dielectric constant along the c-axis is larger than that in the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 11 basal plane [36], therefore, the films with highly preferred orientation along the c-axis have larger dielectric constants than those with random orientations.…”

Microstructure and properties of ZrB2–SiC composites prepared by spark plasma sintering using TaSi2 as sintering additive

“…In previous investigations, it has also been found that the increase of grain size in materials decreases the electrical conductivity. [30][31][32] Probably, it can be explained why ZS1 has the higher electrical conductivity than that of ZS6. Similarly, though (Zr,Ta)B 2 solid solution is the main component in ZS4 and ZS5, the fine-grained microstructure might be the dominant factor for the higher electrical conductivity.…”

High-pressure characterization of the optical and electronic properties of InVO4, InNbO4, and InTaO4

“…Then, assuming an electron mobility of 10 cm 2 / (V s) typical of polycrystalline materials [61] (like our samples), it will lead a resistivity of the order of 10 MΩ cm as measured. The electrical conductivity on InVO 4 has been attributed to the presence of donor states at ~ 0.7 eV below the conduction band [62]. The presence of these donor states has been related mainly to deviations from the ideal In:V ratio of 1:1.…”

“…Notice that a deviation of 0.05% corresponds to a donor density of approximately 6 × 10 19 cm −3 . The low bulk conductivity is because only a small fraction of these donors will be ionized [62].…”