Electron-spin-resonance study of electron properties in nitrogen and carbon austenites

Abstract

Electron-spin resonance was studied in the ${\mathrm{Cr}}_{21}$${\mathrm{Ni}}_{16}$${\mathrm{Mn}}_{7}$ and ${\mathrm{Cr}}_{20}$${\mathrm{Ni}}_{16}$${\mathrm{Mn}}_{6}$ austenites with different content of nitrogen and carbon. Measurements were made in the temperature region 10--300 K. Temperature dependences were obtained for the absorption-derivative signal parameters such as the intensity I(T), the width \ensuremath{\Delta}H(T), and the asymmetry parameter R(T). Theoretical analysis of the signal shape revealed that its temperature dependence is equivalent to its dependence on the inverse length of electron diffusion ${\mathrm{\ensuremath{\delta}}}_{\mathit{e}}$ through the skin layer \ensuremath{\delta}, if the value (\ensuremath{\delta}${\mathrm{\ensuremath{\delta}}}_{\mathit{e}}$) is constant while the temperature changes. The dependence of the electron-state density on the Fermi surface D(${\mathrm{\ensuremath{\varepsilon}}}_{\mathit{F}}$) upon the solutes content is deduced from the fitting of theoretical and experimental curves I(T), \ensuremath{\Delta}H(T), and R(T). It was established that D(${\mathrm{\ensuremath{\varepsilon}}}_{\mathit{F}}$) increases in nitrogen austenite and decreases in carbon austenite with the growth of nitrogen and carbon concentration.