I am working on the electrical resistivity of FeCo alloys. I find this effect in the below book (Page 363 paragraph 2). But, I'm confused because some of the parameters e.g. positive and negative C1 and C2 which presented in this paragraph.
What are C1 and C2?
http://libgen.org/book/index.php?md5=18E98F66743C0CA184B817EBB7C3AEC4