Negative compressibility, negative Poisson's ratio, and stability



The role of negative compressibility is considered in detail. Experimental observations of negative bulk modulus in pre-strained foam are presented and interpreted. A constrained microscopic model which exhibits negative compressibility is proposed. Some other negative and counterintuitive properties of matter, like negative Poisson's ratio, negative thermal expansion, negative specific heat, and negative pressure are also discussed. A simple thermodynamic model with negative thermal expansion is presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)