A doped silica-titania (“DST”) glass article that includes a glass article having a glass composition comprising a silica-titania base glass containing titania at 7 to 14 wt. % and a balance of silica, and a dopant selected from the group consisting of (a) F at 0.7 to 1.5 wt. %, (b) B2O3 at 1.5 to 5 wt. %, (c) OH at 1000 to 3000 ppm, and (d) B2O3 at 0.5 to 2.5 wt. % and OH at 100 to 1400 ppm. The glass article has an expansivity slope of less than about 1.3 ppb/K2 at 20° C. For DST glass articles doped with F or B2O3, the OH level can be held to less than 10 ppm, or less than 100 ppm, respectively. In many aspects, the DST glass articles are substantially free of titania in crystalline form.