Ferromagnetic correlations in heavy fermions from an NMR point of view: YbNi4P2 vs. YbRh2Si2. Issue 3 (18th February 2013)

• Record Type: Journal Article
• Authors: Baenitz, M.; Sarkar, R.; Khuntia, P.; Krellner, C.; Geibel, C.; Steglich, F.; Toropov, Alexey; Ivanov, Sergey
• Is Part Of: Physica status solidi. Volume 10:Issue 3(2013:Mar.)
• Page Start: 540
• Page End: 543
• Publication Date: 2013-02-18
• Subjects: Solid state physics -- Congresses; Solid state physics -- Periodicals; Solid state physics; Conference proceedings; Periodicals; 530.41
• DOI: 10.1002/pssc.201200852
• Languages: English
• ISSNs: 1862-6351

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Ferromagnetic correlations are discussed on the basis of shift <italic>K</italic><sub>4<italic>f</italic></sub> and spin–lattice‐relaxation (SLR) rate <italic>R</italic><sub>4<italic>f</italic></sub>(<italic>T</italic>) = (1/<italic>T</italic><sub>1</sub><italic>T</italic>)<sub>4<italic>f</italic></sub> investigations for YbNi<sub>4</sub>P<sub>2</sub> and YbRh<sub>2</sub>Si<sub>2</sub>. For YbRh<sub>2</sub>Si<sub>2</sub> the coexistence of antiferromagnetic (afm) and ferromagnetic (fm) fluctuations at the edge of magnetic order is strongly related to the non‐Fermi‐liquid behaviour (NFL). The analysis of the NMR results for YbNi<sub>4</sub>P<sub>2</sub> in the modified Korringa framework for correlated local moment metals yields the enhancement factor <tex-math notation="tex"><![CDATA[$\cal K$]]></tex-math><inline-graphic xlink:href="ark:/27927/pgh6nd2hr2" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />(<italic>α</italic>) which is a measure of the <italic>q</italic> ‐space dependence of the complex dynamic susceptibility. Surprisingly the <tex-math notation="tex"><![CDATA[$\cal K$]]></tex-math><inline-graphic xlink:href="ark:/27927/pgh6nd2hqj" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />(<italic>α</italic>) behavior of YbNi<sub>4</sub>P<sub>2</sub>is very similar to YbRh<sub>2</sub>Si<sub>2</sub>and evidences strongly the evolution of an afm (<italic>q ≠</italic> 0) component in the <italic>q =</italic> 0 dominated complex dynamic susceptibility <italic>χ''</italic> (<italic>q, ω<sub>n</sub>, T</italic>) at low temperatures and in small fields. This suggests the presence of ferro‐ and antiferromagnetic fluctuations at the QCP and the freezing out of the afm ones by applying magnetic fields and tuning towards FL state. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)</p> </abstract>