Beyond magnons in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Nd</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>ScNbO</mml:mi><mml:mn>7</mml:mn></mml:msub></mml:mrow></mml:math>: An Ising pyrochlore antiferromagnet with all-in–all-out order and random fields
Allen Scheie, M. B. Sanders, Xin Gui, Yiming Qiu, Timothy R. Prisk, R. J. Cava, C. Broholm
Abstract
Many magnetic materials have quantum disordered magnetic ground states, but it is not always clear what drives them. Here, the authors study the pyrochlore magnet Nd${}_{2}$ScNbO${}_{7}$ using neutron diffraction, heat capacity, and neutron-sampled nuclear hyperfine excitations. The static magnetic moments inferred from these three techniques are inconsistent, pointing to some fraction of spins remaining dynamic to the lowest temperatures -- an observation confirmed by the anomalous low-energy density of states in the specific heat. Similar behavior is seen in Nd${}_{2}$Zr${}_{2}$O${}_{7}$. It could indicate either quantum spin-liquid behavior or local disorder-induced spin singlets.