title: Thermoelectric Properties of Nano-Meso-Micro β-MnO2 Powders as a Function of Electrical Resistance.
abstract: Particle sizes of manganese oxide (β-MnO2) powders were modified by using a mortar and pestle ground method for period of times that varied between 15-60 min. Particle size versus ground time clearly shows the existence of a size-induced regime transition (i.e., regime I and II). Thermoelectric properties of β-MnO2 powders as a function of electrical resistance in the range of R P  = 10 - 80Ω were measured. Based on the data presented, we propose a model for the β-MnO2 system in which nanometer-scale MnO2 crystallites bond together through weak van der Waals forces to form larger conglomerates that span in size from nanometer to micrometer scale.
authors.affiliation: Department Physics and Astronomy, James Madison University, 901 Carrier Drive, 22807, Harrisonburg, Virginia, USA.
authors.forename: Morgan
authors.initials: M
authors.lastname: Hedden
authors.forename: Nick
authors.initials: N
authors.lastname: Francis
authors.forename: Jason T
authors.initials: JT
authors.lastname: Haraldsen
authors.forename: Towfiq
authors.initials: T
authors.lastname: Ahmed
authors.forename: Costel
authors.initials: C
authors.lastname: Constantin