ИСТИНА

The lanthanum aluminate synthesis was carried out in two stages in water vapor medium from mechanical mixtures of lanthanum oxide and aluminum hydroxide. At first, this mixture was treated by water vapor at 200 C (P=1.5 MPa) during 20 – 22 hours. After this stage of synthesis the product represented the mixture of two phases: prismatic crystals of lanthanum hydroxide and disordered boehmite. During treatment of this product in water fluid at 400 C (P=22 MPa) during 18 - 24 hours a diffusion of aluminium into channels of structure of lanthanum hydroxide with formation nanocrystals of lanthanum aluminate in all volume of crystals of lanthanum hydroxide occurs. But for all that, the prismatic crystal shape of lanthanum oxyhydroxide was remained.The finish product was comprised of lanthanum aluminate with the crystal sizes 200 – 500 nm.