Centimeter-Wave Reflection in the Nitrates and Nitrites of Sodium and Potassium: Experiment and Theory

Authors

Steven G. Cornelison, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland
Arthur Guass, Jr., U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland
J. Krane, University of Nebraska - Lincoln
John R. Hardy, University of Nebraska - LincolnFollow

Date of this Version

2-1997

Comments

Published in J. Appl. Phys. 81 (3), 1 February 1997. Copyright © 1997 American Institute of Physics. Used by permission.

Abstract

Temperature-dependent centimeter-wave reflection is studied in powdered samples of potassium nitrate (KNO₃), potassium nitrite (KNO₂), sodium nitrate (NaNO₃), and sodium nitrite (NaNO₂). Temperature-dependent reflection measurements at centimeter-wave frequencies were performed on an HP8510B Network analyzer based reflectometer. These measurements are compared to calculations utilizing a Debye relaxation model. Reflection losses seen in KNO₂ and NaNO₂ are expected to be due to the presence of permanent dipoles that are excited to ‘‘hopping’’ modes as the temperature is raised. Although NaNO₃ shows little reflection losses, KNO₃ shows significant losses as the temperature is raised toward the order/disorder transition temperature of 128 °C. This is believed to be due to the development of ‘‘induced’’ dipole moments as the lattice becomes increasingly disordered.