TY - JOUR
T1 - Synthesis, structure, and properties of tetragonal Sr2 M 3 As2 O2 ( M3 = Mn3, Mn2 Cu, and MnZn2) compounds containing alternating CuO2 -type and FeAs-type layers
AU - Nath, R.
AU - Garlea, V. O.
AU - Goldman, A. I.
AU - Johnston, D. C.
PY - 2010/6/15
Y1 - 2010/6/15
N2 - Polycrystalline samples of Sr2 Mn2 CuAs2 O2, Sr2 Mn3 As2 O2, and Sr2 Zn2 MnAs2 O2 were synthesized. Their temperature- and applied magnetic field-dependent structural, transport, thermal, and magnetic properties were characterized by means of x-ray and neutron diffraction, electrical resistivity ρ, heat capacity, magnetization, and magnetic susceptibility measurements. These compounds have a body-centered-tetragonal crystal structure (space group I4/mmm) that consists of M O2 (M=Zn and/or Mn) oxide layers similar to the CuO2 layers in high superconducting transition temperature Tc cuprate superconductors, and intermetallic MAs (M=Cu and/or Mn) layers similar to the FeAs layers in high- Tc pnictides. These two types of layers alternate along the crystallographic c axis and are separated by Sr atoms. The site occupancies of Mn, Cu, and Zn were studied using Rietveld refinements of x-ray and neutron powder diffraction data. The temperature dependences of ρ suggest metallic character for Sr2 Mn2 CuAs2 O2 and semiconducting character for Sr2 Mn3 As2 O2 and Sr2 Zn2 MnAs2 O2. Sr2 Mn2 CuAs2 O2 is inferred to be a ferrimagnet with a Curie temperature TC =95 (1) K. Remarkably, we find that the magnetic ground-state structure changes from a G -type antiferromagnetic structure in Sr2 Mn3 As 2 O2 to an A -type ferrimagnetic structure in Sr 2 Mn2 CuAs2 O2 in which the Mn ions in each layer are ferromagnetically aligned but are antiferromagnetically aligned between layers.
AB - Polycrystalline samples of Sr2 Mn2 CuAs2 O2, Sr2 Mn3 As2 O2, and Sr2 Zn2 MnAs2 O2 were synthesized. Their temperature- and applied magnetic field-dependent structural, transport, thermal, and magnetic properties were characterized by means of x-ray and neutron diffraction, electrical resistivity ρ, heat capacity, magnetization, and magnetic susceptibility measurements. These compounds have a body-centered-tetragonal crystal structure (space group I4/mmm) that consists of M O2 (M=Zn and/or Mn) oxide layers similar to the CuO2 layers in high superconducting transition temperature Tc cuprate superconductors, and intermetallic MAs (M=Cu and/or Mn) layers similar to the FeAs layers in high- Tc pnictides. These two types of layers alternate along the crystallographic c axis and are separated by Sr atoms. The site occupancies of Mn, Cu, and Zn were studied using Rietveld refinements of x-ray and neutron powder diffraction data. The temperature dependences of ρ suggest metallic character for Sr2 Mn2 CuAs2 O2 and semiconducting character for Sr2 Mn3 As2 O2 and Sr2 Zn2 MnAs2 O2. Sr2 Mn2 CuAs2 O2 is inferred to be a ferrimagnet with a Curie temperature TC =95 (1) K. Remarkably, we find that the magnetic ground-state structure changes from a G -type antiferromagnetic structure in Sr2 Mn3 As 2 O2 to an A -type ferrimagnetic structure in Sr 2 Mn2 CuAs2 O2 in which the Mn ions in each layer are ferromagnetically aligned but are antiferromagnetically aligned between layers.
UR - http://www.scopus.com/inward/record.url?scp=77956323270&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.81.224513
DO - 10.1103/PhysRevB.81.224513
M3 - Article
AN - SCOPUS:77956323270
SN - 1098-0121
VL - 81
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 22
M1 - 224513
ER -