A simple method of direct synthesis of Sr-beta alumina powder is presented. An aqueous suspension of fine milled particles of boehmite or corundum, SrCO3, and Mg(OH)(2) . 4MgCO(3) and/or Li2CO3 is freeze-dried to preserve homogeneity and is subsequently calcined. When corundum is used, the suspension is first heated near the boiling point for 2 h in order to render the corundum more reactive. The powders can be slip-cast into dense, impermeable, thermal shock-resistant tubes suitable for solid electrolyte applications. Other routes to precursor powder formation are examined, and the reaction steps during calcination are elucidated. No technique could be found for the direct synthesis of Sr-beta " alumina. Tubes of this ceramic have been fabricated by ion-exchange of Na-beta " alumina tubes in molten salt baths. The poor thermal shock resistance of these tubes can be remedied by the addition of zirconia toughener.