[en] In electromagnetic heating of ceramic materials like Al₂O₃, ZrO₂, and MgO, the heating rate depends on their ion migration losses, which tend to increase at low frequencies and as the temperature is raised. The frequency and temperature-dependent loss factors of these materials can be qualitatively described using the Maxwell-Boltzmann or the Bose-Einstein distribution function in conjunction with the Debye relaxation theory. Quantitatively, some proposed modeling constant can be determined by curve-fitting various measurements of ceramic materials on loss tangent versus a wide range of temperature at different frequencies reported by Westphal and Sils