Magnetic behaviour of ternary silicides CeT2Si2 (T ≡ Ru, Rh, Pd, Os, Ir, Pt) and boron substitution in Ce{Ru, Os}2Si2−xBx

“…For example, valence fluctuating system CeIr 2 Si 2 shows polymorphism. CeIr 2 Si 2 is found to form in ThCr 2 Si 2 -type body-centered tetragonal structure at low temperature which exhibits Fermi liquid behavior, whereas at high temperature it forms in CaBe 2 Ge 2 -type primitive tetragonal structure that exhibits non-Fermi liquid behavior [15,16].…”

Section: Introductionmentioning

confidence: 99%

Kondo lattice heavy fermion behavior in CeRh₂Ga₂

Anand

Adroja

Bhattacharyya

et al. 2017

J. Phys.: Condens. Matter

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The physical properties of an intermetallic compound CeRhGa have been investigated by magnetic susceptibility [Formula: see text], isothermal magnetization M(H), heat capacity [Formula: see text], electrical resistivity [Formula: see text], thermal conductivity [Formula: see text] and thermopower S(T) measurements. CeRhGa is found to crystallize with CaBeGe-type primitive tetragonal structure (space group P4/nmm). No evidence of long range magnetic order is seen down to 1.8 K. The [Formula: see text] data show paramagnetic behavior with an effective moment [Formula: see text]/Ce indicating Ce valence state of Ce ions. The [Formula: see text] data exhibit Kondo lattice behavior with a metallic ground state. The low-T [Formula: see text] data yield an enhanced Sommerfeld coefficient [Formula: see text] mJ/mol K characterizing CeRhGa as a moderate heavy fermion system. The high-T [Formula: see text] and [Formula: see text] show an anomaly near 255 K, reflecting a phase transition. The [Formula: see text] suggests phonon dominated thermal transport with considerably higher values of Lorenz number L(T) compared to the theoretical Sommerfeld value L .

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“…Even a small change in volume can lead to a drastic change in structural as well as physical properties, for example, Kondo lattice system CeIr 2 Ge 2 which forms in CaBe 2 Ge 2 -type tetragonal structure exhibits heavy fermion behavior, [19][20][21] and valence fluctuating system CeIr 2 Si 2 which shows polymorphism exhibits Fermi liquid behavior in low temperature ThCr 2 Si 2 -type tetragonal structure and non-Fermi liquid behavior in high temperature CaBe 2 Ge 2 -type tetragonal structure. 22,23 Most of the CeT 2 X 2 compounds have been found to crystallize in layered ThCr 2 Si 2 -type bodycentered tetragonal structure which is very favorable for magnetic ordering and superconductivity on account of its centrosymmetric nature. However, there are few compounds that form in different crystal structure.…”

Section: Introductionmentioning

confidence: 99%

Ferromagnetic ordering in CeIr2B2: Transport, magnetization, specific heat, and NMR studies

et al. 2012

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We present a complete characterization of ferromagnetic system CeIr2B2 using powder x-ray diffraction XRD, magnetic susceptibility χ(T ), isothermal magnetization M (H), specific heat C(T ), electrical resistivity ρ(T, H), and thermoelectric power S(T ) measurements. Furthermore 11 B NMR study was performed to probe the magnetism on a microscopic scale. Rietveld refinement of powder XRD data confirms that CeIr2B2 crystrallizes in CaRh2B2-type orthorhombic structure (space group fddd ). The χ(T ), C(T ) and ρ(T) data confirm bulk ferromagnetic ordering with Tc = 5.1 K. Ce ions in CeIr2B2 are in stable trivalent state. Our low-temperature C(T ) data measured down to 0.4 K yield Sommerfeld coefficient γ = 73(4) mJ/mol K 2 which is much smaller than the previously reported value of γ = 180 mJ/mol K 2 deduced from the specific heat measurement down to 2.5 K. For LaIr2B2 γ = 6(1) mJ/mol K 2 which implies the density of states at the Fermi level D(EF ) = 2.54 states/(eV f.u.) for both spin directions. The renormalization factor for quasi-particle density of states and hence for quasi-particle mass due to 4f correlations in CeIr2B2 is ≈ 12. The Kondo temperature TK ∼ 4 K is estimated from the jump in specific heat of CeIr2B2 at Tc. Both C(T ) and ρ(T ) data exhibit gapped-magnon behavior in magnetically ordered state with an energy gap Eg ∼ 3.5 K. The ρ data as a function of magnetic field H indicate a large negative magnetoresistance (MR) which is highest for T = 5 K. While at 5 K the negative MR keeps on increasing up to 10 T, at 2 K an upturn is observed near H = 3.5 T. On the other hand, the thermoelectric power data have small absolute values (S ∼ 7 µV/K) indicating a weak Kondo interaction. A shoulder in S(T ) at about 30 K followed by a minimum at ∼ 10 K is attributed to crystal electric field (CEF) effects and the onset of magnetic ordering. 11 B NMR line broadening provides strong evidence of ferromagnetic correlations below 40 K.

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Magnetic behaviour of ternary silicides CeT2Si2 (T ≡ Ru, Rh, Pd, Os, Ir, Pt) and boron substitution in Ce{Ru, Os}2Si2−xBx

Cited by 46 publications

References 17 publications

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Ce2Ni2Cd—A New Intermediate-Valent Cerium Compound

Kondo lattice heavy fermion behavior in CeRh₂Ga₂

Ferromagnetic ordering in CeIr2B2: Transport, magnetization, specific heat, and NMR studies

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Magnetic behaviour of ternary silicides CeT2Si2 (T ≡ Ru, Rh, Pd, Os, Ir, Pt) and boron substitution in Ce{Ru, Os}2Si2−xBx

Cited by 46 publications

References 17 publications

Ce2Ni2Cd—A New Intermediate-Valent Cerium Compound

Ce2Ni2Cd—A New Intermediate-Valent Cerium Compound

Kondo lattice heavy fermion behavior in CeRh2Ga2

Ferromagnetic ordering in CeIr2B2: Transport, magnetization, specific heat, and NMR studies

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Kondo lattice heavy fermion behavior in CeRh₂Ga₂