Synthesis, crystal structure and physical properties of europium – manganese fluoride pnictides, EuMnPnF (Pn = P, As, Sb)
- The quaternary compounds EuMnPnF (Pn = P, As, Sb) have been prepared via solid state route at 1173 K, and their crystal and electronic structures as well as magnetic and transport properties have been elucidated. These compounds belong to the widespread LaAgSO structure type and crystallize in tetragonal (P4/nmm) unit cells with a = 4.0292(1) Å, c = 8.9505(2) Å for EuMnPF, a = 4.1227(1) Å, c = 9.0846(2) Å for EuMnAsF, and a = 4.3120(1) Å, c = 9.4356(2) Å for EuMnSbF. At low temperatures, the magnetic response is dominated by Eu2+. Contrary to previous reports, we do not observe any magnetic transitions in EuMnPF down to 2 K, whereas its arsenide and antimonide analogs exhibit Eu2+ ordering around 3 K. According to the electrical resistivity measurements and density-functional calculations, all three compounds are narrow-gap semiconductors.
