Adding greek character to axis title

Question

I want to add a greek character to the y-axis of my barplot in R.
The problem is that I need this character to be integrated in the title. I want to write:

Answer 1

I give an updated answer to Chase's plot example (from 2011) above while working with Windows 10 with a suitable TrueType Font with the help package utf8 on R 3.62. In my answer, I assign a value to μ. The unicode characters I just call out by their hex (??) code. The space is just a 'space' inside quotes. See my answer here:

See also: http://www.unicode.org/Public/10.0.0/ucd/UnicodeData.txt

utf8-package {utf8}

# pi small case
utf8_print("\u03C0")
"π"
# sigma small case
utf8_print("\u03C3")
"σ"

μ <- abs(digamma(1))
μseq <- seq(μ,3*μ,μ)
dev.new()
plot(μseq, ylab = "Diameter of apeture ( μ m)",
  , xlab = "Force spaces with ~ μ  \u03C0  \u03C3  \u03C0 ",
  , main = "This is another Greek character with space \u03C3")
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