Synthesis, crystal structure, transport, and magnetic properties of novel ternary copper phosphides, A2Cu6P5 (A = Sr, Eu) and EuCu4P3.

Three new ternary copper phosphides, Sr(2)Cu(6)P(5), Eu(2)Cu(6)P(5), and EuCu(4)P(3), have been synthesized from the elements in evacuated silica capsules. Eu(2)Cu(6)P(5) and Sr(2)Cu(6)P(5) adopt the Ca(2)Cu(6)P(5)-type structure, while EuCu(4)P(3) is isostructural to BaMg(4)Si(3) and still remains the only representative of this structure type among the ternary Cu pnictides. All three materials show metallic conductivity in the temperature range 2 K ≤ T ≤ 290 K, with no indication for superconductivity.