Low temperature formation of (NaxK12x)NbO3 from hydrothermally synthesised NaNbO3

摘要

Na0?5K0?5NbO3 was synthesised by heating a mixture of KNbO3 and NaNbO3 powders to 800uCnand cooling immediately. The KNbO3–NaNbO3 powder mixture was obtained after 10 h ofnreacting NaNbO3 in a 6M KOH solution at 200uC. This reaction caused the dissolution of NaNbO3nand precipitation of KNbO3. The dissolution–reprecipitation process led to an intimate mixture ofnKNbO3 and NaNbO3 powders with much smaller particle sizes and a surface area that was 3?5ntimes greater than the separately hydrothermally synthesised KNbO3 and NaNbO3 powders. Thenincreased surface area, smaller grain sizes and intimate mixing of the powders were responsiblenfor the much faster conversion to a Na0?5K0?5NbO3 solid solution powder.