In the field of non-contact methodology for the evaluation of carrier transport study, microwave Hall mobility technique using bimodal cavity is the most sensitive method available so far. Though there is no constraint for the use of different types or shapes of the bimodal cavities used, each cavity would have its own advantages and disadvantages. In this respect, it is very important to analyze the sensitivity of different cavities that could be used in this methodology. In this paper, different bimodal cavities [TE112 (X-band) cylindrical and TE111 (P-band) cylindrical, TE101 (X-band) cubical and a rectangular bimodal cavity (X-band resonating with TE 103 and TE105 modes)] are used to evaluate the carrier mobility in various semiconductor samples. These cavities are then analyzed in terms of the sensitivity and the percentage of deviation from the DC mobility values. ©2007 The Japan Society of Applied Physics.

Venkatachalam Subramanian

Department Of Physics

Vemuri Rama Krishna Murthy

Constraint theory

Electron mobility

Hall effect

BIMODAL CAVITY

MICROWAVE HALL EFFECT

MICROWAVE HALL MOBILITY

Charge carriers

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IIT Madras

Analysis of Bimodal Cavities for Microwave Hall Effect Measurements

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

Composite nanofibers from poly(methylmethacrylate)- (PMMA-) conducting polyaniline [PANI(HCl)] were prepared by using the electrospinning technique. The morphology and structural details of the fibers were characterized by SEM and the ac conductivity of the composite fibers found was measured to be ∼ 2.17 × 10-4 S/cm which is very good enhancement compared to that of pure PMMA and conductivity of PANI-PMMA thin films as well. The conductivity is found to increase with increase in the polyaniline content in the composite. Microwave Hall mobility measurements on electrospun nanofibers showed 17 cm2/V s for the lower loadings. With further increase in the polyaniline content in the composite, the mobility value decreases which is attributed to the increase in carrier-carrier scatterings. © 2011 American Institute of Physics.

Fulltext

Journal of Applied Physics

Microwave Hall mobility and electrical properties of electrospun polymer nanofibers

Composite fibers of single walled carbon nanotubes dispersed in poly(methyl methacrylate) and polystyrene are prepared using electrospinning. The single fiber electrical conductivity is measured as a function of the composition of carbon nanotubes. A noncontact method of measuring the carrier mobility at microwave frequency (14 GHz) using bimodal cavity is employed. The mobility measurements indicate lower percolation threshold for mobility compared to electrical conduction. For higher concentrations of carbon nanotubes, the mobility is found to decrease indicating possible carrier-lattice scattering. © 2008 American Institute of Physics.

Applied Physics Letters

Microwave Hall mobility studies on polymer-single walled carbon nanotube composite fibers

Films of polymer metal oxide composites with poly(methyl methacrylate) and metallic powders (CuO, Ni, and brushed Fe3O4) were prepared with a spin-casting method. Electric transport studies indicated that the compositions surpassed the percolation threshold limit. Alternating current (AC) conductivity studies confirmed a hopping mechanism with power-law behavior in frequency. For the first time, the mobility values of the carriers in these films were measured by the contactless microwave Hall effect technique with a bimodal cavity operating at 14 GHz. In this technique, a circular bimodal cavity is used to measure the change in the transmission coefficient (proportional to the carrier mobility) due to the application of a static magnetic field perpendicular to the microwave electric fields. The mobility measurements indicated a decrease in mobility with increasing quantity of CuO and Ni and showed an increase in the carrier-lattice scattering, whereas the mobility increased with increasing Fe3O4 due to the negative magneto resistance. © 2007 Wiley Periodicals, Inc.

Journal	Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
ISSN	00214922
Open Access	No