TY - JOUR
T1 - Muon spin relaxation and susceptibility measurements of an itinerant-electron system Sr 1-xCa xRuO 3
T2 - Quantum evolution from ferromagnet to paramagnet
AU - Gat-Malureanu, I. M.
AU - Carlo, J. P.
AU - Goko, T.
AU - Fukaya, A.
AU - Ito, T.
AU - Kyriakou, P. P.
AU - Larkin, M. I.
AU - Luke, G. M.
AU - Russo, P. L.
AU - Savici, A. T.
AU - Wiebe, C. R.
AU - Yoshimura, K.
AU - Uemura, Y. J.
PY - 2011/12/19
Y1 - 2011/12/19
N2 - Muon spin relaxation (μSR) and magnetic susceptibility measurements have been performed in the itinerant-electron magnet Sr 1-xCa xRuO 3, with x= 0.0, 0.3, 0.5, 0.65, 0.7, 0.75, 0.8, 0.9, and 1.0. SrRuO 3 is a ferromagnet with the critical temperature T c∼160 K. Upon (Sr, Ca) substitution, T c decreases monotonically with increasing Ca concentration x and the ferromagnetic order disappears around x= 0.7. Very weak static magnetism is observed in the x= 0.75 and 0.8 systems, while the x= 0.9 and 1.0 systems remain paramagnetic in their full volume. Phase separation between volumes with and without static magnetism was observed in the x= 0.65, 0.7, 0.75, and 0.8 systems, near the magnetic crossover around x= 0.7. In this concentration region, μSR measurements revealed discontinuous evolution of magnetic properties in contrast to magnetization measurements, which exhibit seemingly continuous evolution. Unlike the volume-integrated magnetization measurements, μSR can separate the effects of the ordered moment size and the volume fraction of magnetically ordered regions. The muon spin relaxation rate 1/T 1 exhibits critical slowing down of spin fluctuations near T c in the ferromagnetic systems with x= 0.0-0.65, consistent with the behavior expected in the self-consistent renormalization theory of itinerant electron ferromagnets. The lack of maximum of 1/T 1 in the x= 0.7 system indicates the disappearance of critical slowing down. These results demonstrate a first-order quantum evolution in the ferromagnet to paramagnet crossover near x= 0.7.
AB - Muon spin relaxation (μSR) and magnetic susceptibility measurements have been performed in the itinerant-electron magnet Sr 1-xCa xRuO 3, with x= 0.0, 0.3, 0.5, 0.65, 0.7, 0.75, 0.8, 0.9, and 1.0. SrRuO 3 is a ferromagnet with the critical temperature T c∼160 K. Upon (Sr, Ca) substitution, T c decreases monotonically with increasing Ca concentration x and the ferromagnetic order disappears around x= 0.7. Very weak static magnetism is observed in the x= 0.75 and 0.8 systems, while the x= 0.9 and 1.0 systems remain paramagnetic in their full volume. Phase separation between volumes with and without static magnetism was observed in the x= 0.65, 0.7, 0.75, and 0.8 systems, near the magnetic crossover around x= 0.7. In this concentration region, μSR measurements revealed discontinuous evolution of magnetic properties in contrast to magnetization measurements, which exhibit seemingly continuous evolution. Unlike the volume-integrated magnetization measurements, μSR can separate the effects of the ordered moment size and the volume fraction of magnetically ordered regions. The muon spin relaxation rate 1/T 1 exhibits critical slowing down of spin fluctuations near T c in the ferromagnetic systems with x= 0.0-0.65, consistent with the behavior expected in the self-consistent renormalization theory of itinerant electron ferromagnets. The lack of maximum of 1/T 1 in the x= 0.7 system indicates the disappearance of critical slowing down. These results demonstrate a first-order quantum evolution in the ferromagnet to paramagnet crossover near x= 0.7.
UR - https://www.scopus.com/pages/publications/84855329568
U2 - 10.1103/PhysRevB.84.224415
DO - 10.1103/PhysRevB.84.224415
M3 - Article
AN - SCOPUS:84855329568
SN - 1098-0121
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 22
M1 - 224415
ER -