Crystal growth and magnetic properties of equiatomic CeAl

Pranab Kumar Das,A Thamizhavel

doi:10.1088/1742-6596/592/1/012009

Pranab Kumar Das, A Thamizhavel

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https://doi.org/10.1088/1742-6596/592/1/012009

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Abstract

Single crystal of CeAl has been grown by flux method using Ce-Al self-flux. Several needle like single crystals were obtained and the length of the needle corresponds to the [001] crystallographic direction. Powder x-ray diffraction revealed that CeAl crystallizes in orthorhombic CrB-type structure with space group Cmcm (no. 63). The magnetic properties have been investigated by means of magnetic susceptibility, isothermal magnetization, electrical transport, and heat capacity measurements. CeAl is found to order antiferromagnetically with a Neel temperature TN = 10 K. The magnetization data below the ordering temperature reveals two metamagentic transitions for fields less than 20 kOe. From the inverse magnetic susceptibility an effective moment of 2.66 μB/Ce has been estimated, which indicates that Ce is in its trivalent state. Electrical resistivity data clearly shows a sharp drop at 10 K due to the reduction of spin disorder scattering of conduction electrons thus confirming the magnetic ordering. The estimated residual resistivity ratio (RRR) is 33, thus indicating a good quality of the single crystal. The bulk nature of the magnetic ordering is also confirmed by heat capacity data. From the Schottky anomaly of the heat capacity we have estimated the crystal field level splitting energies of the (2J + 1) degenerate ground state as 25 K and 175 K respectively for the fist and second excited states.

Highlights

IntroductionMagnetism in rare earth intermetallic compounds is interesting due to the competing interaction between Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo exchange interaction
Magnetism in rare earth intermetallic compounds is interesting due to the competing interaction between Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo exchange interaction. Such compounds exhibit various diverse ground states depending on the relative strength of RKKY and Kondo exchange interaction, for example, CeAl3, CeCu6 [1, 2] are heavy-fermion Kondo systems without long range magnetic ordering; CeAl2, CeB6 [3, 4] are Kondo lattice compounds with magnetic ordering at low temperature
We have grown the single crystals of CeAl and LaAl by self flux method

Summary

Introduction

Magnetism in rare earth intermetallic compounds is interesting due to the competing interaction between Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo exchange interaction. Such compounds exhibit various diverse ground states depending on the relative strength of RKKY and Kondo exchange interaction, for example, CeAl3, CeCu6 [1, 2] are heavy-fermion Kondo systems without long range magnetic ordering; CeAl2, CeB6 [3, 4] are Kondo lattice compounds with magnetic ordering at low temperature. In CeIn3, pressure induced superconductivity is observed [5] In view of these interesting properties, rare earth intermetallic compounds, especially Ce-based compounds, where 4f level lies close to the Fermi energy, have been studied extensively over last several decades. In continuation to our investigations on binary Ce compounds, we report here on the magnetic properties of the equiatomic compound CeAl

Discussion

Conclusion