Synthesis and pressure and field-dependent magnetic properties of the kagome-bilayer spin liquid Ca10Cr7 O28

Abstract

We report the synthesis of polycrystalline samples of the recently discovered spin-liquid material Ca10Cr7O28 and present measurements of the ambient and high pressure magnetic susceptibility χ versus temperature T, magnetization M versus magnetic field H at various T, and heat capacity C versus T at various H. The ambient pressure magnetic measurements indicate the presence of both ferromagnetic and antiferromagnetic exchange interactions with dominant ferromagnetic interactions and with the largest magnetic energy scale ∼10 K. The χ(T) measurements under externally applied pressure of up to P≈1 GPa indicate the robust nature of the spin-liquid state despite relative increase in the ferromagnetic exchanges. C(T) shows a broad anomaly at T≈2.4 K which moves to higher temperatures in a magnetic field. The evolution of the low temperature C(T,H) and the magnetic entropy is consistent with frustrated magnetism in Ca10Cr7O28.