Radio-frequency (14.6 MHz) AC magnetic susceptibility, χ A C, of Dy2Ti2O7 was measured using self-oscillating tunnel-diode resonator. Measurements were made with the excitation AC field parallel to the superimposed DC magnetic field up to 5 T in a wide temperature range from 50 mK to 100 K. At 14.6 MHz, a known broad peak of χ AC (T) from kHz - range audio-frequency measurements around 15 K for both  and  directions shifts to 45 K, continuing the Arrhenius activated behavior with the same activation energy barrier of E a ≈ 230 K. Magnetic field dependence of χ AC along  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 features are frequency independent. An unusual upturn of the 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.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- frequency domain
- spin ice