Journal Article

IMPULSE-2017-00039

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Dipolar effects on the critical fluctuations in Fe: Investigation by the neutron spin-echo technique MIEZE

Kindervater, J. (Corresponding author)MLZ* ; Säubert, S.MLZ* ; Böni, P.MLZ*

2017
Inst. Woodbury, NY

Please use a persistent id in citations: doi:10.1103/PhysRevB.95.014429

Abstract: Iron is one of the archetypical ferromagnets to study the critical fluctuations at a continuous phase transition thus serving as a model system for the application of scaling theory. We report a comprehensive study of the critical dynamics at the transition from the ferro- to the paramagnetic phase in Fe, employing the high-resolution neutron spin-echo technique, modulated intensity of zero effort (MIEZE). The results show that the dipolar interactions lead to an additional damping of the critical spin fluctuations at small momentum transfers q. The results agree essentially with scaling theory if the dipolar interactions are taken into account by means of the mode-coupling equations. However, in contrast to expectations, the dipolar wave number qD that plays a central role in the scaling function f(κ/q,qD/κ) becomes temperature dependent. In the limit of small q the critical exponent z crosses over from 2.5 to 2.0.

Keyword(s): Magnetic Materials (1st) ; Magnetism (2nd)

---

Contributing Institute(s):

1. RESEDA
2. E21

Research Program(s):

1. TOPFIT - Topological Spin Solitons for Information Technology (291079) (291079)

Experiment(s):

1. RESEDA: Resonance spin echo spectrometer (NL5S)

Appears in the scientific report 2017

---

Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---