Specific-heat study for ferromagnetic and antiferromagnetic phases in SrRu_{1-x}Mn_xO3

TL;DR

This study investigates how Mn doping affects the electronic, magnetic, and thermal properties of SrRuO3, revealing a transition from ferromagnetic to antiferromagnetic phases and significant changes in specific heat and resistivity.

Contribution

It provides detailed insights into the evolution of electronic and magnetic states in SrRu_{1-x}Mn_xO_3 with doping, highlighting the coupling between disorder, electronic reconstruction, and magnetic phases.

Findings

Ferromagnetic transition anomaly becomes a broad peak with 5% Mn doping.

Low-temperature electronic specific-heat coefficient gamma decreases significantly with Mn doping.

Antiferromagnetic insulating phase emerges at higher Mn concentrations.

Abstract

Low-temperature electronic states in SrRu_{1-x}Mn_xO_3 for x <= 0.6 have been investigated by means of specific-heat C_p measurements. We have found that a jump anomaly observed in C_p at the ferromagnetic (FM) transition temperature for SrRuO_3 changes into a broad peak by only 5% substitution of Mn for Ru. With further doping Mn, the low-temperature electronic specific-heat coefficient gamma is markedly reduced from the value at x=0 (33 mJ/K^2 mol), in connection with the suppression of the FM phase as well as the enhancement of the resistivity. For x >= 0.4, gamma approaches to ~ 5 mJ/K^2 mol or less, where the antiferromagnetic order with an insulating feature in resistivity is generated. We suggest from these results that both disorder and reconstruction of the electronic states induced by doping Mn are coupled with the magnetic ground states and transport properties.