① Ammonia solution was added to La(NO3)3 (1 M, 2 mL) aqueous solution. ② After additional agitation for 1 h, the as-obtained colloidal suspension was transferred to a 50 mL autoclave and heated at 200°C for 24 h.
① 0.003 M CTAB was mixed with deionized water and then 40 mL of NH3·H2O was added. ② 0.004 M LaCl3·6H2O and LnCl3·6H2O with the different Ln compositions were added into the mixture and then heated at 200°C for 4 h.
① La(NO3)3, Yb(NO3)3, and Er(NO3)3 and deionized water were added into a 30 mL Teflon-lined autoclave, followed by adding mixed hydroxides. ② The autoclave was preheated to 200°C for 30 min and then the reaction progressed for 24 h.
① Concentrated NH4OH was dropped to La(NO3)3·6H2O solution until pH at 10. ② Transfer into a Teflon-lined autoclave and heat by a 300 W microwave digestion at 150°C for 1 h.
