Finding escape character in files (PowerShell)

I'm trying to find the carriage return (\r) and new line (\n) in files but the following two statements return nothing:

Get-ChildItem -recurse | Select-String -pattern "\r" | group path | select name
Get-ChildItem -recurse | Select-String -pattern "\n" | group path | select name

However, the tab (\t) escape character seems to work:

Get-ChildItem -recurse | Select-String -pattern "\t" | group path | select name