Sage + Latex - How to change a font for axes label?

edit

I use Sage and LaTeX and when I do this:

\begin{sagesilent}
  p2 = list_plot(zip(H, f(5)), True, color='blue', axes_labels=[u'$H,$ ??',u'$\mu, c$'])
  p2.fontsize(14)
\end{sagesilent}

and run sage DIPLOM.sagetex.sage I get this:

/usr/lib/sagemath/local/lib/python2.7/site-packages/matplotlib/mathtext.py:887: MathTextWarning: Font 'default' does not have a glyph for '\u043a' [U43a]
  MathTextWarning)

So how can I change a font name to use not only latin symbols?

PS: Even here these symbols are displayed as "??". Can't this site handle unicode?