RTD Element

What chemical element are Resistance Temperature Detectors (RTD) typically made out of?

Hint
A RTD is a device used to relate change in resistance to change in temperature.
Hint 2
The resistance temperature coefficient, which is determined by the material a RTD is made out of, is typically $$0.00385^{\circ}C^{-1}$$ .
A RTD is a device used to relate change in resistance to change in temperature. The controlling equation for a RTD is:
$$$R_T=R_0[1+\alpha (T-T_0)]$$$
where $$R_T$$ is the RTD’s resistance at temperature $$T$$ , $$R_0$$ is the RTD’s resistance at the reference temperature $$T_0$$ (usually 0°C), and $$\alpha$$ is the resistance temperature coefficient. The resistance temperature coefficient is determined by the device’s chemical element. Since a RTD is typically made from platinum, usually $$\alpha=0.00385^{\circ}C^{-1}$$ .
Platinum