| | | | | | | webmail : intra-extra| Accès VPN| Accès IST| Contact | Français
 >
 >
img Stress-induced magnetic textures and fluctuating chiral phase in MnGe chiral magnet  
M. Deutsch, P. Bonville, A. V. Tsvyashchenko, L. N. Fomicheva, F. Porcher, F. Damay, S. Petit and I. Mirebeau

img

We have studied the MnGe chiral magnet below TN = 170 K, by magnetic measurements, M¨ossbauer spectroscopy, and by neutron diffraction at ambient and under nonhydrostatic pressure. At ambient pressure, we observe the coexistence of two magnetic phases belonging to the same crystal phase in a large temperature range (down to 100 K) below TN: ferromagnetically correlated rapidly fluctuating spins coexist with frozen spins involved in the helical order. Applying a uniaxial pressure component induces a strong magnetic texture, where most of the helical axes reorient along the stress axis. The magnetic texture persists in the fluctuating chiral state up to TN. Our results suggest that the zero field ground state at ambient pressure is a multidomain state consisting of helical domains with random orientations rather than a three-dimensional skyrmion lattice. They show the presence of an unusually broad transition to paramagnetism with a dynamical phase separation triggered by temperature.
A. Menelle, 2015-01-09 00:00:00

 

Retour en haut