Naslov
Anisotropic physical properties of the Al13Fe4 decagonal approximant and its ternary extension Al13(Fe, Ni)4

Autori
Popčević, Petar ; Smontara, Ana ; Ivkov, Jovica ; Wencka, M. ; Komelj, M. ; Jeglič, P. ; Vrtnik, S. ; Bobnar, M. ; Jagličić, Z. ; Bauer, B. ; Gille, P. ; Borrmann, H. ; Burkhardt, U. ; Yu. Grin, Y. ; Dolinšek, J.

Izvornik
Physical Review B - Condensed Matter and Materials Physics (1098-0121) 81 (2010), 18; 184203-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
61.44.Br; 71.23.Ft

Sažetak
We have investigated magnetic susceptibility, electrical resistivity, specific heat, thermoelectric power, Hall coefficient and thermal conductivity of the Al13Fe4 and Al13(Fe, Ni)4 monoclinic approximants to the decagonal quasicrystal. While the Al13Fe4 crystals are structurally well ordered, the ternary extension Al13(Fe, Ni)4 contains quenched disorder and can be viewed as a disordered version of Al13Fe4 . The crystallographic-direction-dependent measurements were performed along the a*, b and c directions of the monoclinic unit cell, where (a*, c) atomic planes are stacked along the perpendicular b direction. The electronic transport and magnetic properties exhibit significant anisotropy. The stacking b direction is the most conducting direction for the electricity and heat. The effect of quenched disorder in Al13(Fe, Ni)4 is manifested in the large residual resistivity and significantly reduced thermal conductivity of this compound, as compared to the ordered Al13Fe4. Specific heat measurements reveal that the electronic density of states at the Fermi level of both compounds is metallic-high. The anisotropic Hall coefficient reflects complicated structure of the anisotropic Fermi surface that contains electron-like and hole-like contributions. Depending on the combination of directions of the current and magnetic field, electron-like ( Rh<0) or hole-like (RH>0 ) contributions may dominate, or the two contributions compensate each other (RH=0). Similar complicated anisotropic behavior was observed also in the thermopower. The anisotropic Fermi surface was calculated ab-initio using the recently refined Al13Fe4 structural model that is also presented in this work.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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