Naslov
Evolution of electronic scattering on frustrated magnetic system under pressure

Autori
Popčević, Petar ; Batistić, Ivo ; Velebit, Kristijan ; Živković, Ivica ; Barišić, Neven ; Tutiš, Eduard ; Smontara, Ana ; Sidorenko, J. ; Jaćimović, J. ; Tsyrulin, N. ; Piatek, J. ; Berger, H. ; Forro, Laszlo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
From Solid State Physics to Biophysics, ABSTRACTS of the 7th conference / - , 2014

Skup
From Solid State Physics to Biophysics VI, From Basic to Life Sciences 7

Mjesto i datum
Dubrovnik, Hrvatska; Cavtat, Hrvatska, 07.06.2014. - 14.06.2014

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
electronic scattering; magnetic system; pressure

Sažetak
It is well known that RKKY (Ruderman-­‐Kittel-­‐ Kasuya-­‐Yosida) interaction is susceptible to fine tuning. This tuning can be accomplished via change in J (coupling of magnetic moments to conduction electrons) or via change in kF (Fermi wave vector) of conducting electrons. Particularly interesting case is suppression of magnetic ground state by Kondo screening due to increase of the J. Additionally, frustration can bring a new layer of complexity into the system suppressing magnetic transition to lower temperatures. Co1/3NbS2 is such a layered compound where Co atoms are intercalated between metallic NbS2 host layers. Those Co atoms form triangular magnetic lattice exhibiting antiferromagnetic ordering below 26 K. The ordering mechanism is not yet fully understood, although RKKY and super-­‐exchange are most likely driving interactions. Pressure is known to be the major tool to influence and study coupling of magnetic moments to conducting electrons. We performed comprehensive experimental (electrical resistivity and thermopower under pressure, anisotropy of electrical resistivity under pressure, ac and dc magnetic susceptibility, elastic neutron scattering) and theoretical (ab-­‐initio calculations) study of Co1/3NbS2. Frustration, that suppress ordering to much lower temperature than Curie-­‐Weiss temperature, is clearly evidenced in magnetic susceptibility. This suppression of magnetic transition leads to deviation from Curie-­‐Weis law and to development of unusual convex curvature of electrical resistivity with temperature. Furthermore, ferromagnetic canting of antiferromagnetically ordered spins brings in additional interplay between first and second order phase transitions. Coupling of magnetic moments to conducting electrons manifests itself as a kink in the in plane electrical resistivity at the temperature of magnetic ordering. For electrical resistivity along the c-­‐axis, that shows upturn below the magnetic transition temperature, we propose spin blocked electronic transport. Hydrostatic pressure suppresses the magnetic ordering temperature to zero near 2 GPa.[1] Above this pressure new phase (metallic spin-­‐liquid candidate) emerges. And eventually at pressures above 3 GPa a minimum in the resistivity appears indicating Kondo screening. DFT calculations revealed rigid band approximation as reasonable approach, while preliminary results suggest that the pressure driven competition between ferro-­‐ and antiferromagnetic ordering results in the disappearance of magnetic order prior to emergence of Kondo screening.[2] 1. N. Barišić, et al., Phys. Rev. B 84 (2011) 075157. 2. P. Popčević, et al., in preparation.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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