A light-beam-assisted temperature-control system operating within a temperature range from 77 to 180 K is developed for investigating the absorption of electromagnetic waves by high-temperature superconductors in the vicinity of superconducting transition with an ESR spectrometer. The advantage of this system is the feasibility of modulating the temperature of a sample with a frequency of 80 Hz and amplitude of 0.01 -0.1 K. The rms temperature instability over a 5-min time interval is within 0.06 K, the temperature gradient in a sample is 0.01 K/mm for T=90 K, and the system relaxation time is 1 - 10 s. The microwave absorption peaks in the vicinity of the superconducting transition of an Y-Ba-Cu-O, single crystal were first measured at (the simultaneous application of magnetic and temperature modulations.
@article{arxiv.cond-mat/9809372,
title = {ESR Spectrometry of High-Temperature Superconductors with Temperature-Modulation-Based Thermoregulation},
author = {M. K. Aliev and G. R. Alimov and I. Kholbaev and T. M. Muminov and B. Olimov and B. Yu. Sokolov and R. R. Usmanov},
journal= {arXiv preprint arXiv:cond-mat/9809372},
year = {2019}
}