Crystal Structure and Thermoelectric Properties of YAl₃C₃

Abstract

The crystal structure of YAl3C3 was refined from laboratory X‐ray powder diffraction data (CuKα1) using the Rietveld method. The crystal structure is hexagonal (space group P63mc, Z=2) with lattice dimensions a=0.342157(4) nm, c=1.72820(1) nm, and V=0.175217(3) nm3. The final reliability indices were Rwp=9.94% (Rwp/Re=1.18), Rp=7.36%, RB=1.77%, and RF=1.03%. The compound shows an intergrowth structure with electroconductive [YC2] thin slabs separated by Al4C3‐type [AlC] layers. This material had thermoelectric properties superior to those of the layered carbides Zr2[Al3.56Si0.44]C5, Zr2Al3C4, and Zr3Al3C5 in the temperature range of 500– 1073 K, with a maximal power‐factor value of 1.96 × 10−4 W·(m·K2)−1 at 1073 K.

[Zr0.72Y0.28]Al4C4: A new member of the homologous series (MC)l(T4C3)m (M=Zr, Y and Hf, T=Al, Si and Ge)

“…The former carbide is isostructural with (ZrC) 2 Al 3 C 2 . The latter carbide, together with (ScC)Al 3 C 2 [13] and (YC)Al 3 C 2 [14,15], can be regarded as the intergrowth structure consisting of the [RC 2 ] slabs separated by the Al 4 C 3 -type [Al 3 C 3 ] layers, where R ¼ U, Sc and Y. Accordingly, these layered carbides are of the members with n ¼ 1 for the homologous series (RC) n Al 3 C 2 (R ¼ Zr, U, Sc and Y, n ¼ 1, 2 and 3).…”

Exploration of novel inorganic compounds using diffractometry and microscopy toward innovative functions

“…6). 31)33) The signs of S were necessarily negative for these compounds irrespective of temperature, suggesting the predominant negative mobile charge carriers. The absolute value of S was the largest for YAl 3 C 3 among the five types of layered carbides, which steadily increased to 112¯V/K with increasing temperature up to 1073 K [ Fig.…”

“…3). 31) In 2007, we have discovered a new quaternary layered carbide Zr 2 (Al,Si) 4 C 5 , which is trigonal (space group R3m and Z = 3) with the unit-cell dimensions of a = 0.33106 nm and c = 4.0945 nm.…”

Thin Film Synthesis of New Nanolaminated Ternary Carbides

“…one X layer for n = 1; two for n = 2; three for n = 3, and therefore the size of the unit cell increases, as shown in Figure Illustrations of MnAl3Cn+2 (left) and MnAl4Cn+3 (center) nanolaminated carbides with n = 2, assigned to space group 186 ( 6 ) and 160 ( 3 ) according to Ref. [26] and [58]. The crystal structure of Al4C3 (right) is given to show the similarity with above phases.…”