Possible magnetism based on orbital motion of protons in ice

TL;DR

This paper reports a magnetic susceptibility anomaly in ice near 60 K, suggesting proton orbital motion may induce magnetism, challenging the traditional view of ice's magnetic properties.

Contribution

It proposes a novel mechanism where proton tunneling in ice induces magnetic fields, potentially explaining observed anomalies and expanding understanding of magnetic phenomena in molecular solids.

Findings

Peak anomaly in magnetic susceptibility near 60 K

Inverted ferromagnetic hysteresis observed at low fields

Proton tunneling may generate induced magnetic fields

Abstract

A peak anomaly is observed in the magnetic susceptibility as a function of temperature in solid H2O near Tp=60 K. At external magnetic fields below 2 kOe, Tp becomes positive in the temperature range between 45 and 66 K. The magnetic field dependence of the susceptibility in the same temperature range exhibits an inverted ferromagnetic hysteretic loop superimposed on top of the diamagnetic signature of ice at fields below 600 Oe. We suggest that a fraction of protons that are capable of undergoing correlated tunneling in a hexagonal path without disrupting the stoichiometry of the lattice create an induced magnetic field opposite to the induced magnetic field created by the electrons upon application of an external field which counters the overall diamagnetism of the material.