TY - JOUR
T1 - Magnetic neutron diffraction study of Ba(Fe1-xCo x)2As2 critical exponents through the tricritical doping
AU - Pajerowski, D. M.
AU - Rotundu, C. R.
AU - Lynn, J. W.
AU - Birgeneau, R. J.
PY - 2013/4/9
Y1 - 2013/4/9
N2 - We present temperature dependent magnetic neutron diffraction measurements on Ba(Fe1-xCox)2As2 for x=0.039, 0.022, and 0.021 as-grown single crystals. Our investigations probe the behavior near the magnetic tricritical point in the (x,T) plane, xtr≈0. 022, as well as systematically exploring the character of the magnetic phase transition across a range of doping values. All samples show long-range antiferromagnetic order that may be described near the transition by simple power laws, with β=0.306±0.060 for x=0.039, β=0.208±0. 005 for x=0.022, and β=0.198±0.009 for x=0.021. For the x=0.039 sample, the data are reasonably well described by the order parameter exponent β=0.326 expected for a three-dimensional Ising model while the x=0.022 and x=0.021 samples are near the β=0.25 value for a tricritical system in the mean-field approximation. These results are discussed in the context of existing experimental work and theoretical predictions.
AB - We present temperature dependent magnetic neutron diffraction measurements on Ba(Fe1-xCox)2As2 for x=0.039, 0.022, and 0.021 as-grown single crystals. Our investigations probe the behavior near the magnetic tricritical point in the (x,T) plane, xtr≈0. 022, as well as systematically exploring the character of the magnetic phase transition across a range of doping values. All samples show long-range antiferromagnetic order that may be described near the transition by simple power laws, with β=0.306±0.060 for x=0.039, β=0.208±0. 005 for x=0.022, and β=0.198±0.009 for x=0.021. For the x=0.039 sample, the data are reasonably well described by the order parameter exponent β=0.326 expected for a three-dimensional Ising model while the x=0.022 and x=0.021 samples are near the β=0.25 value for a tricritical system in the mean-field approximation. These results are discussed in the context of existing experimental work and theoretical predictions.
UR - http://www.scopus.com/inward/record.url?scp=84876189270&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.87.134507
DO - 10.1103/PhysRevB.87.134507
M3 - Article
AN - SCOPUS:84876189270
SN - 1098-0121
VL - 87
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 13
M1 - 134507
ER -