Radio-frequency (14.6 MHz) AC magnetic susceptibility, χAC′, of \dytio\ was measured using a self-oscillating tunnel-diode resonator. Measurements were made with the excitation AC field parallel to the superimposed DC magnetic field up 5 T in a wide temperature range from 50 mK to 100 K. At 14.6 MHz a known broad peak of χAC′(T) from kHz - range audio-frequency measurements around 15~K for both [111] and [110] directions shifts to 45~K, continuing the Arrhenius activated behavior with the same activation energy barrier of Ea≈230~K. Magnetic field dependence of χAC′ along [111] reproduces previously reported low-temperature two-in-two-out to three-in-one-out spin configuration transition at about 1~T, and an intermediate phase between 1 and 1.5~T. The boundaries of the intermediate phase show reasonable overlap with the literature data and connect at a critical endpoint of the first-order transition line, suggesting that these low-temperature features are frequency independent. An unusual upturn of magnetic susceptibility at T→0 was observed in magnetic fields between 1.5~T and 2~T for both magnetic field directions, before fully polarized configuration sets in above 2~T.
@article{arxiv.2105.12218,
title = {Low-temperature high-frequency dynamic magnetic susceptibility of classical spin-ice Dy$_2$Ti$_2$O$_7$},
author = {S. Teknowijoyo and K. Cho and E. I. Timmons and M. A. Tanatar and J. W. Krizan and R. J. Cava and R. Prozorov},
journal= {arXiv preprint arXiv:2105.12218},
year = {2022}
}