Structure Study of Polycrystalline $Na_3YSi_3O_9$ and Its Substitutes Related to $Na_4CaSi_3O_9,\;Ca_3Al_2O_6$ Structure

摘要: The study of the structure, by x-ray diffraction and infrared spectrum, showed that is similar to except for its being pseudo-cubic instead cubic. peaks in pattern could therefore be indexed on basis cell. Also, modified (M = Lu, Yb, Tm, Er, Y, Ho, Dy, Gd, Eu, Sm) type compounds were synthesized introducing excess sodium, decreasing M(III) concentration, substituting small amount phosphorus silicon. unit cell parameters composition estimated from powder patterns using Cohen method.