TY - JOUR
T1 - Exploring the limits of the zintl concept for the A14MPn11 structure type with M = Zn, Cd
AU - Young, Dianna M.
AU - Torardi, Charles C.
AU - Olmstead, Marilyn M.
AU - Kauzlarich, Susan M.
PY - 1995
Y1 - 1995
N2 - A14ZnSb11+x and A14CdSb11+x (A = Ca, Sr) are synthesized by reacting elements in a 14: 1:11 ratio at 1000°C. Low-temperature (130 K) single-crystal X-ray diffraction data shows that these compounds are tetragonal, space group I41/acd, Z = 8, and are structurally similar to previously studied A14MPn11 (A = Ca, Sr, Ba; M = Al, Ga, Mn; Pn = As, Sb, Bi) compounds. However, these Zn and Cd compounds with the exception of Sr14ZnSb11 contain additional Sb and cannot be understood according to simple Zintl electron counting rules. Low-temperature lattice parameters, R1(wR2) are Ca14ZnSb11.20, a = 16.778 (3), c = 22.088 (6) Å, R1(wR2) = 0.063 (0.115); Ca14CdSb11.43, a = 16.583 (3), c = 23.167 (7) Å, R1(wR2) = 0.0353 (0.0792); Sr14ZnSb11, a = 17.569 (5), c = 22.961 (6) Å, R1(wR2) = 0.0486 (0.0997); Sr14CdSb11.37, a = 17.637 (3), c = 23.163 (4) Å, R1(wR2) = 0.0627 (0.1435). Temperature-dependent resistivity measurements show that these materials are semiconducting in behavior with small activation energies: Ca14ZnSb11.20: Ea = 3.9(1) × 10-3 eV; Ca14CdSb11.43, Ea = 7.6(1) × 10-2 eV; Sr14ZnSb11, Ea = 1.5(1) × 10-2 eV; Sr14CdSb11.37, Ea = 1.1(1) × 10-2 eV. Several simple models are presented in order to understand the crystallographic results.
AB - A14ZnSb11+x and A14CdSb11+x (A = Ca, Sr) are synthesized by reacting elements in a 14: 1:11 ratio at 1000°C. Low-temperature (130 K) single-crystal X-ray diffraction data shows that these compounds are tetragonal, space group I41/acd, Z = 8, and are structurally similar to previously studied A14MPn11 (A = Ca, Sr, Ba; M = Al, Ga, Mn; Pn = As, Sb, Bi) compounds. However, these Zn and Cd compounds with the exception of Sr14ZnSb11 contain additional Sb and cannot be understood according to simple Zintl electron counting rules. Low-temperature lattice parameters, R1(wR2) are Ca14ZnSb11.20, a = 16.778 (3), c = 22.088 (6) Å, R1(wR2) = 0.063 (0.115); Ca14CdSb11.43, a = 16.583 (3), c = 23.167 (7) Å, R1(wR2) = 0.0353 (0.0792); Sr14ZnSb11, a = 17.569 (5), c = 22.961 (6) Å, R1(wR2) = 0.0486 (0.0997); Sr14CdSb11.37, a = 17.637 (3), c = 23.163 (4) Å, R1(wR2) = 0.0627 (0.1435). Temperature-dependent resistivity measurements show that these materials are semiconducting in behavior with small activation energies: Ca14ZnSb11.20: Ea = 3.9(1) × 10-3 eV; Ca14CdSb11.43, Ea = 7.6(1) × 10-2 eV; Sr14ZnSb11, Ea = 1.5(1) × 10-2 eV; Sr14CdSb11.37, Ea = 1.1(1) × 10-2 eV. Several simple models are presented in order to understand the crystallographic results.
UR - http://www.scopus.com/inward/record.url?scp=0002316099&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0002316099&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0002316099
VL - 7
SP - 93
EP - 101
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 1
ER -