In looking over what starting materials I have here, I don't have any good cesium starting materials. Before I purchase some, I figured I'd bounce it off the group in case someone has some to share (or maybe access to a reuse facility). To start, the materials do not need to be particularly pure, and only once everything is working well (prepare crystals (PXRD), it's water insoluble, polishes nicely, holds up to the beam, looks homogeneous...), then I can pick up purer starting materials. To prepare the flux(es), any of the following would work as a cesium source: Cs, Cs2O, CsOH, CsOH•H2O, Cs2CO3, CsHCO3, CsOAc (CH3COOCs, cesium acetate), HCOOCs (cesium formate), Cs3PO4, Cs2HPO4, or CsH2PO4. If you have any you can share, let me know, otherwise I'll try to place an order for some starting materials soon. I'm not sure if CsZrOPO4 will work, but at least Cs2Zr(PO4)2 and CsZr2(PO4)3 have been prepared. There are also some Cs/Ti/P/O's. I probably ought to do some literature searches too and see what I can dig up!