Frustrated magnetism of the maple-leaf-lattice antiferromagnet MgMn3O7·3H2O
Physical review B
We present a novel hydrated layered manganate MgMn_3O_7·3H_2O as a maple-leaf-lattice (MLL) antiferromagnet candidate. The MLL is obtained by regularly depleting 1/7 of the lattice points from a triangular lattice so that the magnetic connectivity z = 5 and is thus intermediately frustrated between the triangular (z = 6) and kagomé (z = 4) lattices. In MgMn_3O_7·3H_2O, the Mn^4+ ions, carrying Heisenberg spin 3/2, form a regular MLL lattice in the quasi-two-dimensional structure. Magnetization
... nd heat capacity measurements using a hydrothermally-prepared powder sample reveal successive antiferromagnetic transitions at 5 and 15 K. A high-field magnetization curve up to 60 T at 1.3 K exhibits a multi-step plateau-like anomaly. We discuss the unique frustration of the MLL antiferromagnet in which the chiraldegree of freedom may play an important role.