NMR Study of MnSi under Pressure

TL;DR

This study uses NMR to investigate how pressure affects the magnetic properties and local electronic environment of MnSi, revealing persistent local magnetic order beyond the critical pressure.

Contribution

It provides a systematic NMR analysis of MnSi under pressure, showing local magnetic order persists above the known critical pressure.

Findings

Local magnetic order remains above P_c=14.8 kbar.

Pressure causes a weak variation in local electronic spin polarization.

Magnetic and non-magnetic Mn atoms coexist under pressure.

Abstract

The magnetic phase diagram $T_c(P)$ of the weak itinerant helimagnetic compound MnSi is reviewed upon a Nuclear Magnetic Resonance (NMR) experiment. We present a systematic study on the evolution of the NMR spin echo signal at $T=1.4$ K of the non-magnetic silicone sites, $^{29}$Si, up to 17.8 kbar. The pressure effect is interpreted as a weak variation of the local electronic spin polarization and the coexistence of magnetic and non magnetic Mn atoms under pressure. From the volume dependence of $f_0$ ($P$), we show notably that a local magnetic order remains above the critical pressure of $P_c=14.8$ kbar.