TY - JOUR
T1 - Field evolution of the magnetic structures in Er2 Ti2 O7 through the critical point
AU - Cao, H. B.
AU - Mirebeau, I.
AU - Gukasov, A.
AU - Bonville, P.
AU - Decorse, C.
PY - 2010/9/28
Y1 - 2010/9/28
N2 - We have measured neutron-diffraction patterns in a single-crystal sample of the pyrochlore compound Er2 Ti2 O7 in the antiferromagnetic phase (T=0.3 K), as a function of the magnetic field, up to 6 T, applied along the [110] direction. We determine all the characteristics of the magnetic structure throughout the critical point at Hc =2 T. As a main result, all Er moments align along the field at Hc and their values reach a minimum. Using a four-sublattice self-consistent calculation, we show that the evolution of the magnetic structure and the value of the critical field are rather well reproduced using the same anisotropic exchange tensor as that accounting for the local paramagnetic susceptibility. In contrast, an isotropic exchange tensor does not yield the correct moment variations through the critical point. The model also accounts semiquantitatively for other experimental data obtained in previous works, such as the field dependence of the heat capacity, energy of the dispersionless inelastic modes and transition temperature.
AB - We have measured neutron-diffraction patterns in a single-crystal sample of the pyrochlore compound Er2 Ti2 O7 in the antiferromagnetic phase (T=0.3 K), as a function of the magnetic field, up to 6 T, applied along the [110] direction. We determine all the characteristics of the magnetic structure throughout the critical point at Hc =2 T. As a main result, all Er moments align along the field at Hc and their values reach a minimum. Using a four-sublattice self-consistent calculation, we show that the evolution of the magnetic structure and the value of the critical field are rather well reproduced using the same anisotropic exchange tensor as that accounting for the local paramagnetic susceptibility. In contrast, an isotropic exchange tensor does not yield the correct moment variations through the critical point. The model also accounts semiquantitatively for other experimental data obtained in previous works, such as the field dependence of the heat capacity, energy of the dispersionless inelastic modes and transition temperature.
UR - http://www.scopus.com/inward/record.url?scp=77957588342&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.82.104431
DO - 10.1103/PhysRevB.82.104431
M3 - Article
AN - SCOPUS:77957588342
SN - 1098-0121
VL - 82
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 10
M1 - 104431
ER -