$\mu$SR study of spin freezing and persistent spin dynamics in NaCaNi${}_2$F${}_7$

Abstract

A new pyrochlore compound, NaCaNi${}_2$F${}_7$, was recently synthesized and has a single magnetic site with spin-1 Ni${}^{2+}$. We present zero field (ZF) and longitudinal field (LF) muon spin rotation ($\mu$SR) measurements on this pyrochlore. Density functional theory (DFT) calculations show that the most likely muon site is located between two fluorine ions, but off-centre. A characteristic F-$\mu$-F muon spin polarization function is observed at high temperatures where Ni spin fluctuations are sufficiently rapid. The Ni${}^{2+}$ spins undergo spin freezing into a disordered ground state below 4~K, with a characteristic internal field strength of 140~G. Persistent Ni spin dynamics are present to our lowest temperatures (75~mK), a feature characteristic of many geometrically frustrated magnetic systems.

References in corpus (23)

• Magnetic Pyrochlore Oxides
• musrfit: A free platform-independent framework for muSR data analysis
• Muon Spin Relaxation Investigation of the Spin Dynamics of Geometrically Frustrated Antiferromagnets Y2Mo2O7 and Tb2Mo2O7 Static Critical Behavior of the Spin-Freezing
• Spin Freezing in Geometrically Frustrated Antiferromagnets with Weak Disorder
• Spin glass transition in geometrically frustrated antiferromagnets with weak disorder
• Experimental Insights into Ground State Selection of Quantum XY Pyrochlores
• Quantum states of muons in fluorides
• Magnetic density of states at low energy in geometrically frustrated systems
• Liquid-like correlations in single crystalline Y2Mo2O7: an unconventional spin glass
• Unconventional Magnetic Ground State in Yb${}_2$Ti${}_2$O${}_7$
• Ab initio strategy for muon site assignment in wide band gap fluorides
• Spin-glass transition in bond-disordered Heisenberg antiferromagnets coupled with local lattice distortions on a pyrochlore lattice
• Single-ion properties of the $S_{eff}$ = 1/2 XY antiferromagnetic pyrochlores, Na$A^{\prime }$Co${}_2$F${}_7$ ($A^{\prime }=$ Ca${}^{2+}$, Sr${}^{2+}$)
• A single crystal high-temperature pyrochlore antiferromagnet
• Orbital Dimer Model for Spin-Glass State in Y${}_2$Mo${}_2$O${}_7$
• Static and dynamic XY-like short-range order in a frustrated magnet with exchange disorder
• Cluster-glass phase in pyrochlore XY antiferromagnets with quenched disorder
• Universal Dynamic Magnetism in Yb-Pyrochlores with Disparate Ground States
• XY Antiferromagnetic Ground State in the Effective S=1/2 Pyrochlore Yb2Ge2O7
• NaSrMn2F7, NaCaFe2F7, and NaSrFe2F7: novel single crystal pyrochlore antiferromagnets
• Competing phases and topological excitations of spin-one pyrochlore antiferromagnets
• Spin freezing in the disordered pyrochlore magnet NaCaCo${}_2$F${}_7$: NMR studies and Monte-Carlo simulations
• Study of the ground state properties of $LiH{o}_x{Y}_{1-x}{F}_4$ using $\mu$SR

Cited by in corpus (8)

• Dynamical structure factor of the three-dimensional quantum spin liquid candidate NaCaNi${}_2$F${}_7$
• Frustrated Magnetism in Fluoride and Chalcogenide Pyrochlore Lattice Materials
• Magnetism and spin dynamics of an S=3/2 frustrated trillium lattice antiferromagnet K2CrTi(PO4)3
• Structural and spin-glass properties of single crystal $J_{eff}$ = 1/2 pyrochlore antiferromagnet NaCdCo${}_2$F${}_7$ : correlating $T_f$ with magnetic-bond-disorder
• Glassy disordered ground states in the frustrated pyrochlore and fluorite antiferromagnets NaCd$M_2$F${}_7$ ($M$ = Ni${}^{2+}$, Mn${}^{2+}$)
• Coexistence of anomalous spin dynamics and weak magnetic order in a chiral trillium lattice K2FeSn(PO4)3
• Magnetism of kagome metals $\left({\text{Fe}}_{1-x}{\text{Co}}_x\right)\text{Sn}$ studied by $\mu$SR
• Spin liquid state in a three-dimensional pyrochlore-like frustrated magnet