Two-pulse stimulated echo in magnets

TL;DR

This paper experimentally investigates two-pulse stimulated echo phenomena in different ferromagnetic materials, revealing distinct relaxation behaviors and mechanisms influencing nuclear magnetic relaxation in these systems.

Contribution

It classifies ferromagnets into two types based on the presence of single-pulse echo and analyzes relaxation times and mechanisms in two-pulse stimulated echoes.

Findings

Short relaxation times are less than the spin-spin relaxation time.

Long relaxation times are close to the transverse relaxation time of single-pulse echo.

Different materials exhibit distinct echo formation mechanisms.

Abstract

The results of experimental study of two-pulse stimulated echo in ferromagnets of two types are presented. Ferromagnet Co and half-metal Co MnSi 2, in which a single-pulse echo formed by the distortion mechanism of the fronts of exciting pulse is also observed, are classified among the first type. Lithium ferrite and intermetal compound MnSb characterized by the absence of single-pulse echo in them - belong to the second type. For signals of two-pulse stimulated echo in the materials of the first type a short time and a long time of relaxations are observed. The short time is about the order of value shorter less than the spin-spin relaxation time. The long time is close to the transverse relaxation time of single-pulse echo formed by the distortion mechanism. The mechanisms that provide the possible interpretations of the peculiarities of the processes of nuclear magnetic relaxation are discussed.