typo fix

src/2_debye_model.md

@@ -134,8 +134,8 @@ T_D = fit[0][0]
 fig, ax = pyplot.subplots()
 ax.scatter(T, c)
 ax.set_title('Heat capacity of silver compared to the Debye and Einstein models')
-ax.plot(temp, c_debye(temp, T_D), label=f'Debye model, $T_e={T_E:.5}$')
-ax.plot(temp, c_einstein(temp, T_E), label=f'Einstein model, $T_e={T_E:.5}$')
+ax.plot(temp, c_debye(temp, T_D), label=f'Debye model, $T_D={T_D:.5}$')
+ax.plot(temp, c_einstein(temp, T_E), label=f'Einstein model, $T_E={T_E:.5}$')
 ax.set_ylim(bottom=0, top=3)
 ax.set_xlim(0, 215)
 ax.set_xlabel('$T(K)$')