LiHoF${}_4$: Cuboidal Demagnetizing Factor in an Ising Ferromagnet

Abstract

The demagnetizing factor has an important effect on the physics of ferromagnets. For cuboidal samples it depends on susceptibility and the historic problem of determining this function continues to generate theoretical and experimental challenges. To test a recent theory, we measure the magnetic susceptibility of the Ising dipolar ferromagnet LiHoF${}_4$, using samples of varying aspect ratio, and we reconsider the demagnetizing transformation necessary to obtain the intrinsic material susceptibility. Our experimental results confirm that the microscopic details of the material significantly affect the transformation, as predicted. In particular, we find that the uniaxial Ising spins require a demagnetizing transformation that differs from the one needed for Heisenberg spins and that use of the wrong demagnetizing transformation would result in unacceptably large errors in the measured physical properties of the system. Our results further shed light on the origin of the mysterious `flat' susceptibility of ordered ferromagnets by demonstrating that the intrinsic susceptibility of the ordered ferromagnetic phase is infinite, regardless of sample shape.

arXiv comment8 pages, 4 figures

References in corpus (10)

• Magnetic Monopoles in Spin Ice
• Theory of the Magnetic phase diagram of LiHoF${}_4$
• Topological Hysteresis in the Intermediate State of Type-I Superconductors
• Collective Phenomena in the LiHo_xY_{1-x}F4 Quantum Ising Magnet: Recent Progress and Open Questions
• Crystal Shape-Dependent Magnetic Susceptibility and Curie Law Crossover in the Spin Ices Dy2Ti2O7 and Ho2Ti2O7
• Special temperatures in frustrated ferromagnets
• The Newtonian Potential and the Demagnetizing Factors of the General Ellipsoid
• The ferromagnetic transition and domain structure in LiHoF4
• Microscopic Aspects of Magnetic Lattice Demagnetizing Factors
• Absence of Domain Wall Roughening in a Transverse Field Ising Model with Long-Range Interactions

Cited by in corpus (3)

• Emergence of mesoscale quantum phase transitions in a ferromagnet
• A Gallery of Soft Modes: Theory and Experiment at a Ferromagnetic Quantum Phase Transition
• Magnetostatic modes and criticality in quantum-Ising materials