Check around for solar cell soldering flux, it might help.
I remember reading in a very old Popular Mechanic (not that I am very old, I just like reading the old stuff) the following trick: On a wheel (like, a sharpening stone wheel), you grind some solder. Then from the same wheel, you barely touch the material you want to solder to, transferring, via friction, the solder from the wheel to the , in your case, ceramic. They stated it worked for glass as well. I presume a low temperature solder would be great for that trick. And use flux as well. I REALLY love that solar cell flux, 'comes in a pen. Read the instructions, it's drippy.