Thermal expansion of the Kondo insulator CeRhSb

Abstract

Thermal expansion of the Kondo insulator CeRhSbNolten, A.J.; de Visser, A.; Kayzel, F.E.; Franse, J.J.M.; Tanaka, H.; Takabatake, T. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. AbstractThe linear coefficients of thermal expansion, a(T), of the Kondo insulator CeRhSb and its non-f-electron analog LaRhSb have been measured on polycrystalline samples in the temperature range 1.5-200 K. After subtracting the phonon contribution (0 o = 260 K), the f-electron contribution to the thermal expansion, am(T), shows two distinct features, a broad maximum is centered at 125 K, while a large shoulder appears below 40 K. In a plot of t~., / T versus T, a maximum appears at the temperature where the energy gap opens, Tg = 10 K. For T < Tg, a.,(T) follows an aT + bT 2 law, which is compatible with a description of the energy gap vanishing on lines at the Fermi surface.

Review on magnetic and related properties of RTX compounds

“…The results show two distinct features, a broad maximum around 125 K, a large shoulder below 40 K and a temperature where the energy gap opens, Tg=10 K [587]. The pressure dependence of thermal expansion in CeRhSb shows that the temperature at which it shows maximum increases with increase in pressure, which is also in agreement with the pressure dependent resistivity data [588].…”

“…The thermal expansion measurement was performed on CeRhSb and the phonon contribution was subtracted using LaRhSb analog [587]. The results show two distinct features, a broad maximum around 125 K, a large shoulder below 40 K and a temperature where the energy gap opens, Tg=10 K [587].…”

Interplay between heavy fermions and crystal-field excitation in Kondo lattices: Low-temperature thermodynamics and inelastic neutron scattering spectra of CeNiSn

“…This means that the electron contribution to the heavy fermion density of states in good samples can be as large as ≈ 50 per cent in agreement with the theoretical predictions for the spin liquid state of the Kondo lattices [22]. It is seen from figure 12, that the theoretical curve describes quite well the temperature behavior of C/T = γ + bT at low temperture and gives the maximum of C/T at T = 6 K. The latter is observed for the more perfect samples [21] where the data for higher temperatures are available.…”

“…( 21) and (22). It is obvious that the covalent repulsion B Γ c of the localized levels E Γ from the free conduction band states above the Fermi level (21,22) is governed by the value of hybridization matrix elements |V i kΓ | 2 . Since the Fermi surface of CeNiSn is dominated by the p-partial waves [19], the hybridization is largest for the j z = ±1/2 and j z = ±3/2 components of the f-states.…”

Band Gap Stability in Kondo Insulators

“…Several experiments, carried out independently, have indicated the same change of the resistivity below Τ = 40 K either for CeRhSb or for CeNiSn [8,39,40]. The coefficient of the volume expansion of CeRhSb has also shown a distinct contribution, which coincided with a change of resistivity [41]. The abnormal change of the volume expansion coefficient α seems to be analogous to that observed below Τ = 40 K in ZrNiSn, therefore, we suggest to attribute the same reasons to explain the volume and resistivity anomalies at Τ < 40 K in the ZrNiSn-type semi-Heusler alloys and in CeNiSn-type Kondo insulators.…”