2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98086It is shown that the dependence of negative thermal expansion coefficient of many substances on the temperature contradicts to an important thermodynamic relation. It is supposed that there are oscillations at the Cp(T) and alpha(T) curves at alpha>0 and they are in reverse phases.6 pages, 7 figures. E-mail me istepanov@email.comGeneral Physicstext