Inverted hysteresis and negative remanence in a homogeneous antiferromagnet

Abstract

Magnetic remanence - found in bar magnets or magnetic storage devices - is probably the oldest and most ubiquitous phenomenon underpinning technological applications of magnetism. It is a macroscopic non-equilibrium phenomenon: a remanent magnetisation appears when a magnetic field is applied to an initially unmagnetised ferromagnet, and then taken away. Here, we present an inverted magnetic hysteresis loop in the pyrochlore compound Nd${}_2$Hf${}_2$O${}_7$: the remanent magnetisation points in a direction opposite to the applied field. This phenomenon is exquisitely tunable as a function of the protocol in field and temperature, and it is reproducible as in a quasi-equilibrium setting. We account for this phenomenon in considerable detail in terms of the properties of non-equilibrium population of domain walls which exhibit a magnetic moment between domains of an ordered antiferromagnetic state which itself has zero net magnetisation. Properties and (non-equilibrium) dynamics of topological defects play an important role in modern spintronics, and our study adds an instance where a uniform field couples selectively to domain walls rather than the bulk.

5 pages, 3 figures in main article and 7 pages, 13 figures in supplementary materials

References in corpus (9)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Antiferromagnetic spintronics
• Tetrahedral Magnetic Order and the Metal-Insulator Transition in the Pyrochlore Lattice of Cd2Os2O7
• All-in all-out magnetic order and propagating spin-waves in Sm2Ir2O7
• Direct Evidence for the 'All-in/All-out' Magnetic Structure in the Pyrochlore Iridates from $\mu$SR
• The quantum origins of moment fragmentation in Nd2Zr2O7
• All-in/all-out magnetic domains: X-ray diffraction imaging and magnetic field control
• Muon spin relaxation and inelastic neutron scattering investigations of all-in/all-out antiferromagnet Nd2Hf2O7
• Evolution of antiferromagnetic domains in the all-in-all-out ordered pyrochlore Nd${}_2$Zr${}_2$O${}_7$

Cited by in corpus (6)

• Monopole density and antiferromagnetic domain control in spin-ice iridates
• Anisotropic exchange Hamiltonian, magnetic phase diagram and domain inversion of Nd${}_2$Zr${}_2$O${}_7$
• Magnetization beyond the Ising limit of Ho${}_2$Ti${}_2$O${}_7$
• Pinch points and half-moons in dipolar-octupolar Nd${}_2$Hf${}_2$O${}_7$
• Field-temperature phase diagram of the enigmatic Nd${}_2$(Zr${}_{1-x}$Ti${}_x$)${}_2$O${}_7$ pyrochlore magnets
• Tuning interactions in the spin-ice materials Dy${}_2$Ge${}_{2-x}$Si${}_x$O${}_7$ by silicon substitution