Synthesis and structural and magnetic characterization of mixed manganese-copper n=1 Ruddlesden-Popper phases

New n = 1 Ruddlesden-Popper phases containing manganese and copper have been synthesized. Their structure has been investigated by X-ray and neutron powder diffraction and found to be tetragonal (I4/ mmm) at temperatures down to 10 K. The series of materials LaxSr2-xMn0.5Cu0.5O4 (x = 0.75, 1, 1.25, 1.5) displays significant Jahn-Teller distortions of the B site cations, with the degree of distortion increasing with x. The materials LaSrMn0.5Cu0.5O4, PrSrMn0.5Cu0.5O4, and NdSrMn0.5Cu0.5O4 show interesting magnetic behavior with antiferromagnetic ordering, but evidence of some ferromagnetic interactions. LaSrMn0.5Cu0.5O4 has long-range antiferromagnetic ordering and La1.5Sr0.5Mn0.5Cu0.5O4 shows more complex behavior due to competing interactions, possibly resulting in a canted magnetic ground state.