Synthesis, Crystal Structure, and Compressibilities of Mn 3− x Ir 5 B 2+ x (0≤ x ≤0.5) and Mn 2 IrB 2

The new ternary transition metal borides Mn 3‐ x Ir 5 B 2+ x (0≤ x ≤0.5) and Mn 2 IrB 2 were synthesized from the elements under high temperature and high‐pressure/high‐temperature conditions. Both phases can be synthesized as powder samples in a radio‐frequency furnace in argon atmosphere. High‐pressure/high‐temperature conditions were used to grow single‐crystals. The phases represent the first ternary compounds within the system Mn–Ir–B. Mn 3− x Ir 5 B 2+ x (0≤ x ≤0.5) crystallizes in the Ti 3 Co 5 B 2 structure type ( P 4/ mbm ; no. 127) with parameters a =9.332(1), c =2.896(2) Å, and Z =2. Mn 2 IrB 2 crystallizes in the β‐Cr 2 IrB 2 crystal structure type ( Cmcm ; no. 63) with parameters a =3.135(3), b =9.859(5), c =13.220(3) Å, and Z =8. The compositions of both compounds were confirmed by EDX measurements and the compressibility was determined experimentally for Mn 3− x Ir 5 B 2+ x and by DFT calculations for Mn 2 IrB 2 .