Comparative study of helimagnets MnSi and Cu2OSeO3 at high pressures

Abstract

The heat capacity of helical magnets Cu2OSeO3 and MnSi has been investigated at high pressures by the ac-calorimetric technique. Despite the differing nature of their magnetic moments, Cu2OSeO3 and MnSi demonstrate a surprising similarity in behavior of their magnetic and thermodynamic properties at the phase transition. Two characteristic features of the heat capacity at the phase transitions of both substances (peak and shoulder) behave also in a similar way at high pressures if analyzed as a function of temperature. This probably implies that the longitudinal spin fluctuations typical of weak itinerant magnets like MnSi contribute little to the phase transition. The shoulders of the heat capacity curves shrink with decreasing temperature suggesting that they arise from classical fluctuations. In case of MnSi the sharp peak and shoulder at the heat capacity disappear simultaneously probably signifying the existence of a tricritical point and confirming the fluctuation nature of the first order phase transition in MnSi as well as in Cu2OSeO3.

References in corpus (4)

• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
• Ultrasonic studies of the magnetic phase transition in MnSi
• Peculiar behavior of the electrical resistivity of MnSi at the ferromagnetic phase transition

Cited by in corpus (12)

• Dramatic pressure-driven enhancement of bulk skyrmion stability
• Magnetic Fluctuations, Precursor Phenomena and Phase Transition in MnSi under Magnetic Field
• Room-temperature skyrmion phase in bulk Cu2OSeO3 under high pressures
• Phase transitions in chiral magnets from Monte Carlo simulations
• Universality of the helimagnetic transition in cubic chiral magnets: Small angle neutron scattering and neutron spin echo spectroscopy studies of Fe${}_{1-x}$Co${}_x$Si
• Skyrmions and spirals in MnSi under hydrostatic pressure
• Magnetization of the Mn${}_{1-x}$Fe${}_x$Si in high magnetic field up to 50 T: possible evidence of a field-induced Griffiths phase
• Increasing the skyrmion stability in Cu${}_2$OSeO${}_3$ by chemical substitution
• Physical properties of (Mn 0.85 Fe 0.15) Si along the critical trajectory
• Monte Carlo modeling the phase diagram of magnets with the Dzyaloshinskii - Moriya interaction
• Tuning the structure of Skyrmion lattice system Cu2OSeO3 under pressure
• Structure analysis of high-pressure phase for skyrmion-hosting multiferroic Cu2OSeO3