This thesis is a study of how to grow the HTSC cuprate, La2−xSrxCuO4 (LSCO). The TravelingSolvent Floating-Zone (TSDZ) method was used to produce LSCO crystals. LCO was doped with Strontium, in order to produce LSCO, in the following amounts: x = 0.02, 0.03, 0.04, 0.05, 0.06, and 0.07. Measurements on the produced crystals have then been performed at Risø-DTU, Denmark and PSI, Switzerland. X-ra...