Update 2_debye_model_solutions.md

src/2_debye_model_solutions.md

@@ -13,7 +13,7 @@ jupyter:
 ---
 
 ```python tags=["initialize"]
-from matplotlib import pyplot
+from matplotlib import pyplot as plt
 from mpl_toolkits.axes_grid1 import make_axes_locatable
 
 import numpy as np