Electron-quasiparticle Interaction Function Research Articles

Electron-quasiparticle Interaction in HoB12

Results of electron-quasiparticle interaction function measurements in intermetallic compound HoB12 studied by point-contact spectroscopy are presented. The temperature behaviour of point contact spectra in heterocontact arrangement between HoB12 and Cu, Pt and Mo counterelectrodes (below and above TN=7.5 K) has revealed three main nonlinearities at 5.5, 10 and 16 meV which have a crystalline electric field origin.

Electron-quasiparticle interaction in the melt-spun cubic RECu5 (RE – heavy rare earth)

The point contact spectroscopy investigations of cubic RECu 5 (RE = Tb, Dy, Ho, Er and Tm) binary compounds prepared by melt-spinning method have been compared. The measured point-contact spectra of RECu 5 -Cu heterocontacts in a spectroscopic regime are directly proportional to the electron-quasiparticle interaction function. The common feature of spectra of all compounds is the broad maximum at about 18-19 meV connected with the electron-phonon interaction. The observed low energy structures (usually below 12 meV) clearly exhibit the crystalline electric field origin.

Point Contact Spectroscopy of the Melt-Spun Cubic TbCu5

The point contact spectra (directly proportional to the electron-quasiparticle interaction function) of heterocontacts between the cubic melt-spun TbCu5 and Cu have been investigated in a spectroscopic regime. A broad peak at 18 meV is connected with electron-phonon interaction. The observed structure in the low energy range below 11 meV has the crystal electric field origin.

Electron-quasiparticle interaction and electrical resistivity of cubic HoCu 5

Point-contact (PC) spectroscopy and temperature dependence of the electrical resistivity ρ( T) have been combined to study the electron–quasiparticle interaction function and transport properties of the cubic (AuBe 5-structure type) HoCu 5 prepared by melt spinning. The ρ( T) dependence revealed two anomalies at ∼3 and ∼8 K. The peaks observed in the low energy part of PC spectrum (∼1.2, ∼4.3 meV) have the crystalline electric field origin. The broad maximum at about 19 meV is connected with phonons of HoCu 5.

Electron–quasiparticle interaction and electrical resistivity of cubic TmCu 5

We have studied the electron–quasiparticle interaction function using point-contact (PC) spectroscopy and electrical resistivity of the cubic phase (structure type AuBe 5) of melt-spun TmCu 5. In the temperature dependence of electrical resistivity no evidence has been found for a magnetic ordering transition above 2 K. The observed peak in the low energy range at about 2.2 meV and small shoulders at 7.8 and 12 meV have their origin in the crystalline electric field (CEF) (the excitations of 4f electrons from ground CEF level to higher excited levels). The broad maximum at about 20 meV is connected with phonons of TmCu 5.

Electron Transport and Point Contact Spectroscopy of Cubic DyCu5

The electron transport properties and point contact spectra of melt-spun DyCu 5 with the cubic phase (structure type AuBe 5 , space group F43m) were investigated. It was found by ac-susceptibility measurements that below a transition temperature Tm = 6.5 K this phase shows metamagnetism. Between Tm and Tc = 14.5 K a spontaneous magnetization is found. Our measurements of electrical resistivity confirm the existence of two magnetic phase transitions in the compound. Furthermore, we present point contact spectra of DyCu5 -Cu heterocontacts which are directly proportional to the electron—quasiparticle interaction function. Apart from a peak at about 18 meV, which is characteristic of electron—phonon interaction in pure Cu, we observed a series of additional maxima at lower energy, which are connected with the allowed 4f-transitiοns from the ground state to excited crystalline electric field levels.

Point-contact spectroscopy of DyNi 5

We have studied the electron—quasiparticle interaction function in the oriented hexagonal single crystal DyNi 5 using the point-contact (PC) spectroscopy above and below T N = 11.6 K. The observed peaks in the low-energy range up to ≈ 10 meV have the crystalline electric field (CEF) origin (the excitations of 4f electrons from ground CEF level to higher excited levels). The broad maximum at about 18 meV is connected with phonons DyNi 5.

Point-contact spectroscopy of the electron–phonon interaction in RENi 5 (RE-rare earths)

The comparison of the characteristic point-contact spectra of heterocontacts between RENi 5 (RE=La, Ce, Pr, Nd, Sm, Dy, Y) and Cu is presented. It is shown that in all samples the contribution of the electron–phonon interaction to the electron–quasiparticle interaction function is qualitatively similar. This observation reflects the very similar lattice constants for all RENi 5 and supports the manner of subtracting the phonon part of electrical resistivity of bulk RENi 5 samples.

POINT-CONTACT SPECTROSCOPY OF THE ELECTRON-PHONON INTERACTION IN SmNi5

The measured point-contact (PC) spectra of the heterocontact between oriented hexagonal single crystal of SmNi 5 and Cu in ballistic and thermal regime are presented. The PC spectrum (the second derivative of I–V characteristic - d 2 I/dV 2( eV )) is directly proportional to the electron-quasiparticle interaction (EQI) function. The absence of the magnetic field effect on the energy position of the characteristic peaks until 10T is the confirmation of the phonon origin. The phonon part of the EQI function is similar to the electron-phonon interaction function for LaNi 5.