Competing ground states in triple-layeredSr4Ru3O10

Abstract

Sr 4 Ru 3 O 10 is characterized by a sharp metamagnetic transition and ferromagnetic behavior occurring within the basal plane and along the c-axis, respectively. Resistivity at magnetic field, B, exhibits low-frequency quantum oscillations when B||c-axis and large magnetoresistivity accompanied by critical fluctuations driven by the metamagnetism when B⊥c-axis. The complex behavior evidenced in resistivity, magnetization and specific heat presented is not characteristic of any obvious ground states, and points to an exotic state that shows a delicate balance between fluctuations and order.

Specific heat of Sr4Ru3O10

“…However, the magnetic properties, reflecting the complex competition between (in-plane) antiferromagnetic and (interplane) ferromagnetic interactions, are unique in that there appears to be an "easy-plane", rather than an easy-axis, for the antiferromagnetic order. The interlayer resistivity drops by an order of magnitude below T M , presumably due to a reduction in spin scattering, but, reflecting the layered structure, stays more than an order of magnitude greater than the basal plane resistivity [3]. Surprisingly, only in the interplayer resistvity are Shubnikov-de Haas oscillations discerned [3].…”

“…The interlayer resistivity drops by an order of magnitude below T M , presumably due to a reduction in spin scattering, but, reflecting the layered structure, stays more than an order of magnitude greater than the basal plane resistivity [3]. Surprisingly, only in the interplayer resistvity are Shubnikov-de Haas oscillations discerned [3].…”

“…In addition, a contribution to the heat capacity ∝ T 3/2 is observed at low temperatures, signaling the ambiguity of the ground state mentioned above [3].…”

“…For example, triple layered Sr 4 Ru 3 O 10 has magnetic and resistive anomalies at T C ≈ 102 K and T M ≈ 50 K [3]. T C marks the onset of apparent ferromagnetic order, with the easy axis normal to the RuO 6 layers, but with saturated moments markedly less than the expected value of two Bohr magnetons per (S=1) Ru 4+ ion.…”

“…Measurements were made both on crystals grown in an image furnace and crystals from reference [3], grown using a flux technique. The structures and stoichiometries of the samples were verified by results of powdered crystal x-ray diffraction and electron dispersive x-ray (EDX).…”