Tetsutaro Inoue

Magnetic and Thermal Properties of CeIrIn5 and CeRhIn5

We studied the magnetic properties in a non-magnetic heavy-fermion compound CeIrIn 5 and an antiferromagnetic compound CeRhIn 5 with the tetragonal structure. High-field magnetization of CeIrIn 5 s...

Magnetic properties of a pressure-induced superconductor UGe2

We performed DC-magnetization and neutron scattering experiments under pressure P for a pressure-induced superconductor UGe 2 . We found that the magnetic moment is enhanced at a characteristic temperature T * in the ferromagnetic state, where T * is smaller than a Curie temperature T C . This enhancement becomes remarkable in the vicinity of P C * =1.20 GPa, where T * becomes 0 K and the superconducting transition temperature T SC shows a maximum. The characteristic temperature T * , which decreases with increasing pressure, also depends on the magnetic field.

Electronic States of the Antiferromagnet UGa3

We have grown a single crystal with the residual resistivity ratio of 81, and studied its electronic properties of the cubic antiferromagnetic compound UGa 3 . From the transverse magnetoresistance...

Metamagnetic magnetization of heavy fermion single crystal UPd2Al3 in high magnetic fields

Abstract High field magnetization and magnetoresistance of a single crystal UPd 2 Al 3 are investigated up to 50 Tesla (T) and a sharp metamagnetic magnetization is observed in the c -plane at 18 T. The metamagnetism is explained by assuming the magnetization-dependent heavy fermion energy.

Fermi Surface Properties of the Enhanced Pauli Paramagnet UAl3.

We succeeded in growing a high-quality single crystal of UAl 3 with the cubic AuCu 3 -type structure and studied the Fermi surface properties by measuring the de Haas–van Alphen (dHvA) effect and t...

Oscillatory High-Field Magnetization in LaP Doped with Ce

A clear de Haas-van Alphen (dHvA) oscillation has been found in LaP doped with 2 atomic percent of Ce under a pulsed field up to 30 Tesla (T) at liquid helium temperature. The oscillation is superimposed on the paramagnetic saturation curve of Ce which does not show the Kondo effect. The Fourier spectrum of the magnetization curves gives an extremal cross-sectional area of the Fermi surface of 0.01 A -2 , which is about a half-value of CeP. The ground state of the Ce atom is investigated by electron spin resonance (ESR) and a nearly isotropic g -value of 1.37 is obtained, in agreement with the theoretical expectation for Γ 7 , while the g -value of field-cooled CeP is 2.93 which is close to that of Γ 8 . The discrepancy is discussed using the neutron diffraction data.

High-Field Magnetic Phase Transitions in CeP

The high-field magnetization of low carrier semimetallic CeP is investigated in the temperature region from 1.3 K to 77 K and applied fields in the {100} and {110} planes up to 64 Tesla (T). A ferrimagnetic state in the low field region changes to an antiferromagnetic state by the application of the field below 10 T. Above 20 T, multi-step magnetizations of the Ce moment related with the Landau level crossing of the conduction electron are observed. The critical fields are almost temperature independent below 35 K. This phenomenon is explained by the Stoner-Landau model that the spin population change in the low concentration conduction electron system at the crossing field induces magnetic phase changes in the Ce spin system. Each critical field is angular dependent.

High-field magnetism of Kondo semiconductors CeNiSn and CeRhSb

Abstract The longitudinal magnetoresistance of the Kondo semiconductor single crystals CeNiSn and CeRhSb are investigated up to 36 T below 4.2 K. Large negative magnetoresistances are found at low temperatures with the field along the b- and c-axis, similar to the field direction along the a-axis in the previous study.

Multi-step magnetization of CeP and CeAs in high magnetic field

Abstract High field magnetizations of CeP and CeAs single crystals are investigated up to 64 T. The successive multi-step magnetizations are found in not only CeP but also CeAs and the critical fields lie with equal spacing on the 1/ H scale. The mechanism of the multi-step magnetizations are discussed.

Heavy Fermion breaking by high magnetic field in single crystal UPd2Al3

Abstract The high field magnetizations of hexagonal UPd 2 Al 3 in various field directions are investigated up to 50 Tesla (T). The angular dependence of the step-magnetization field shows a large anisotropy in the ac -plane and the spin system can be regarded as the XY -spin model except for a very small anisotropy in the c -plane. The observed step-magnetization is explained by introducing the model that the heavy Fermion state is broken by the magnetic field at the critical field and the exchange interaction is reduced by the change in the carrier density.