R(T) Explorer — three materials, one temperature axis

Pick a material class and drag the temperature across the stage range (−190 °C to 600 °C). The curve is the textbook model for that class; the marker shows where your setpoint sits and which transport regime governs it.

Model honesty: the metal is a Bloch–Grüneisen phonon term (Debye temperature 343 K, representative of copper) plus a residual-resistivity floor; the semiconductor is an illustrative 1.12 eV-gap model with a 0.16 eV donor activation energy (10¹⁵ cm⁻³ donors) and T^−3/2 phonon mobility, plotted on a logarithmic axis; the superconductor is a metallic normal state ending in a narrow phenomenological transition at T_c = 90 K (−183 °C). The 90 K transition is likewise illustrative — real onset, midpoint, zero-resistance temperature and width depend on composition, oxygen content, current density and sample connectivity. The slope readout is the normalized derivative d[R/R(300 K)]/dT. Curves are representative model shapes with illustrative parameters — not digitized data for any specific material.