ChemInform Abstract: Lanthanum Triel/Tetrelides La(Al,Ga)_x(Si,Ge)_1‐x. Experimental and Theoretical Studies on the Stability of Intermetallic 1:1 Phases.

Abstract

C h emIn fo rm 2 0 1 2 , 4 3 , issu e 1 0 © 2 0 1 2 Wiley -VCH Verl ag G m b H & Co. K G a A , We i n he i m Struct ure D 2 000 DOI: 1 0.100 2/ch in.201 2100 03 L ant hanum Tr iel/Te tr elide s La(A l,Ga)x(S i , G e) 1-x. Experiment a l and Theo retical Studie s on the Stability of Inte rme tallic 1:1 Phase s. -Phas e f or mation at th e bi nary se ctio ns La Si-La Ga and La Ge -LaA l ar e cha r ac ter ize d by XR D a nd FP-LAPW ele ctronic ban d structure ca lcula tions. The com poun ds are o btain ed from melts of the ele ments . La Si and LaGa 0. 10Si0. 90 c rysta llize in t he o r th orhomb ic spac e g r o up Pnm a with Z =4 (FeB-type struc ture). La Ga0. 25Si0. 75, LaG a 0. 47Si0. 53, LaG a 0. 73Si0. 27, a nd LaGa crystalliz e in the o r th orhomb ic spac e g r o up Cmc m with Z = 4 (Cr B-type str u cture ) . La Ge a n d L a A l 0. 15Ge 0. 85 cr ys talliz e in the orthorhom bic s pa c e group Pnm a w ith Z = 4 ( F eB -t yp e st r u ct u r e ) . L a Al 0. 42Ge 0. 58, L aA l0. 54Ge0. 46, a nd La Al0. 61Ge 0. 39 cr ys talliz e in the orthorhom bic sp ace grou p Cmcm with Z = 4 ( CrB-ty pe struc ture). The ne w com pound La 2Al 2G e c r y sta llize s in the orthorhom bic spa ce group Cmc m with Z = 8 (V2B 3-ty p e s t r u ct u r e ) . T h i s co m p o un d co m b i ne s t h e s t r u ct u r a l el e me n t s o f t h e C r B / F e B st r u c t ur e f a mily ( two-bon ded M atom s) with th e trigon ally plan ar bon ded M atom s of the ThSi2 type with a fully o r d ered Al a nd Ge a tom d istribu tion a nd thu s without pha se width . -( DU E RR , I . ; B AU E R, B. ; R O EH R* , C . ; Z . Na t ur f or sc h. , B : C hem . S ci . 66 ( 201 1) 11, 1 107 -1 121 ; I n st. Anorg . Ana l. Chem ., Alb ert-Ludwigs-Univ., D-791 04 Fr e iburg /B r., Germa ny; Ger., Abstr. Eng .) -W. Pe we sto r f 10 -00 3