Ferromagnetism and crystal fields inYbInNi4

Abstract

We present transport and thermodynamic measurements as a function of temperature ͑0.1-300 K͒, pressure ͑1 bar-16 kbars͒, and magnetic field ͑0-600 kOe͒ on YbInNi 4. Ferromagnetism arises near 3 K out of a state with enhanced electronic specific-heat coefficient. Resistivity, specific-heat, and magnetization measurements imply that the ground state of YbInNi 4 is a crystal-field doublet, whereas earlier neutron-scattering results suggest a ground-state quartet. We also compare YbInNi 4 to YbInCu 4 and intermediate alloys. ͓S0163-1829͑98͒00613-4͔

Magnetic Field Induced Orbital Polarization in CubicYbInNi4: Determining the Quartet Ground State Using X-Ray Linear Dichroism

“…Figure 1 summarizes some crystal-field scenarios which have been suggested for this system: inelastic neutron scattering studies infer a |Γ 8 quartet ground state [23], while specific heat, magnetization and ESR experiments claimed to have found a |Γ 7 doublet ground state [24,25]. Yet, one can envision even another scenario: measurements on YbInCu 4 with 50% Y doping proposed a CF scheme with a quasi-quartet ground state as shown on the right in Fig.…”

“…However, here we demonstrate that the application of a magnetic field can provide key information about the nature of the ground state wave function. We have done so using YbInNi 4 as an exemplary model system: it has the relative simplicity of a stable valent system and yet there is a long standing debate about its ground state wave function [23][24][25]. Very recently, also a new interesting scenario has been proposed for the closely related compound Yb 0.5 Y 0.5 InCu 4 [26].…”

“…The static susceptibility of YbInNi 4 shows a CurieWeiss behavior with nearly the full Yb 3+ moment down to about 3 K where it orders magnetically [24]. In the cubic C15b structure of YbInNi 4 the 8 fold degenerate Hund's rule ground state of Yb 3+ with J=7/2 splits in cubic site symmetry into two doublets |Γ 6 and |Γ 7 , and one quartet |Γ 8 which can be written in a |J z basis as…”

Crystal field study in rare-earth-dopedLuInNi4

“…7,10,11 The crystalline electric-field splitting in this compound appears to be comparable to the spinfluctuation temperature and consequently does not significantly influence the ground state. [7][8][9][10][11][12][13] In contrast, CFE and the RKKY interactions are dominant for YbAuCu 4 , YbPdCu 4 , and YbInNi 4 .…”

“…13 Resistivity, specific heat, and magnetization measurements 13 15 Because the crystal-field scheme, and associated ground-state degeneracy, is important for guiding the interpretation of the low-T properties of these materials, we have performed further CFE investigations in rare-earth-doped LuInNi 4 in order to understand the role of CFE in YbInNi 4 and the different observation reported in Refs. 13 and 14.…”