Synthesis and Crystal Structure of a New Layered Carbide [Zr_1.97Y_0.03]Al₄C₅

Abstract

A new layered carbide, [Zr1.97Y0.03]Al4C5, has been synthesized and characterized by X‐ray powder diffraction (XRPD), transmission electron microscopy, and energy‐dispersive X‐ray spectroscopy (EDX). The atom ratios [Zr:Y] were determined by EDX, and the crystal structure was refined from laboratory XRPD data (CuKα1) using the Rietveld method. The crystal is trigonal (space group R3m, Z=3) with lattice dimensions of a=0.331934(4) nm, c=4.09459(3) nm, and V=0.390701(7) nm3. The final reliability indices were Rwp=10.29% (S=1.31), Rp=7.45%, RB=1.63%, and RF=1.04%. The compound shows an intergrowth structure with NaCl‐type [Zr1.97Y0.03C3] thin slabs separated by Al4C3‐type [AlC] layers. This material is isostructural with Zr2[Al3.56Si0.44]C5.

Zirconium Aluminum Carbides: New Precursors for Synthesizing ZrO2–Al2O3 Composites

“…When these Y‐containing solid solutions are oxidized, YSZ–Al 2 O 3 composites are expected to form. Recently, [Zr(Y)] 2 Al 4 C 5 31 and YAl 3 C 3 , 64 which have similar structure to Zr 2 Al 3 C 4 have been successfully synthesized. Other Y‐containing zirconium aluminum carbides are also expected to form easily.…”

“…Recently, layered ternary carbides in Zr–Al–C system, such as Zr 2 Al 3 C 4 , 18,19 Zr 3 Al 3 C 5 , 20–22 Zr 4 Al 3 C 6 , 23 Zr 5 Al 6 C 9 , 23 Zr 7 Al 6 C 11 , 23 ZrAl 4 C 4 , 24 Zr 2 Al 4 C 5 , 25 Zr 3 Al 4 C 6 , 25 and ZrAl 8 C 7 26 as well as some associated solid solutions Zr 2 [Al(Si)] 4 C 5 , 27–29 Zr 3 [Al(Si)] 4 C 6 , 28–30 and [Zr(Y)] 2 Al 4 C 5 31 were synthesized and characterized. The crystal structures of these compounds are composed of two basic units: one is the (ZrC) m ( m =1, 2, 3, 4, 5, and 7) slab in the NaCl‐type structure; and the other one is aluminum carbide (Al 3 C 2 for Zr 2 Al 3 C 4 , Zr 3 Al 3 C 5 , Zr 4 Al 3 C 6 , Zr 5 Al 6 C 9 , Zr 7 Al 6 C 11 ; Al 4 C 3 for ZrAl 4 C 4 , Zr 2 Al 4 C 5 , Zr 3 Al 4 C 6 , and ZrAl 8 C 7 ) in the Al 4 C 3 ‐type structure 23–32 . For solid solutions, partial Al is replaced by Si, or Zr is replaced by Y in the crystals 27–31 .…”

“…The crystal structures of these compounds are composed of two basic units: one is the (ZrC) m ( m =1, 2, 3, 4, 5, and 7) slab in the NaCl‐type structure; and the other one is aluminum carbide (Al 3 C 2 for Zr 2 Al 3 C 4 , Zr 3 Al 3 C 5 , Zr 4 Al 3 C 6 , Zr 5 Al 6 C 9 , Zr 7 Al 6 C 11 ; Al 4 C 3 for ZrAl 4 C 4 , Zr 2 Al 4 C 5 , Zr 3 Al 4 C 6 , and ZrAl 8 C 7 ) in the Al 4 C 3 ‐type structure 23–32 . For solid solutions, partial Al is replaced by Si, or Zr is replaced by Y in the crystals 27–31 . Because of strong covalent bonds, i.e.…”

[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)

“…Therefore the general formula has to be expanded to (Zr 1Àx Y x-C) l {(Al lÀyÀz Si y Ge z ) 4 C 3 } m , where the maximum x-, y-and z-values were 0.02, 0.07 and 0.02, respectively [1,[7][8][9][10][11]. After the publication of papers on Zr 2 (Al,Si) 4 C 5 [8] and Zr 3 (Al,Si) 4 C 6 [7], the isomorphous crystal structures were reported in the Hf-Al-C system for Hf 2 Al 4 C 5 and Hf 3 Al 4 C 6 [12].…”

“…The [Al 4m C 3m+1 ] layers were incorporated by several amounts of Si [1,[7][8][9] and/or Ge [10] components, whereas considerable amount of Y [11] component dissolved into the [Zr l C l+1 ] layers. Therefore the general formula has to be expanded to (Zr 1Àx Y x-C) l {(Al lÀyÀz Si y Ge z ) 4 C 3 } m , where the maximum x-, y-and z-values were 0.02, 0.07 and 0.02, respectively [1,[7][8][9][10][11].…”