Transition Of Gd3 Research Articles

Optical luminescence of electronic and vibronic transitions in Gd 2− xY x(SO 4) 3 · 8H 2O

X-ray and ultraviolet-excited emission spectra of Gd 2(SO 4) 3 · 8H 2O show the electronic 6P 3/2,5/2,7/2, → 8S 7/2,lines of Gd 3+ accompanied by vibronics involving the water and sulfate vibrations. Removal of the water of hydration by heating eliminates the water vibronics, while the spectrum of Gd 2(SO 4) 3 · 8D 2O exhibits the expected shift toward the electronic origin of vibronics attributed to the water of hydration. In a dilute system of composition Gd 0.8Y 1.2(SO 4) 3 · 8H 2O we also see the 6D J, 6I J → 8S 7/2level transitions.

Chiroptical activity of 8S → 6P transitions in gadolinium pyrogermanate single crystal

The circular dichroism spectra corresponding to 8S 1/2 → 6P 1/25/23/2 transitions of Gd 3+ in chiral pyrogermanate single crystal have been obtained at room temperature. The asymmetry factors are calculated and compared with experiment.

Resonance second-harmonic generation in rare earth crystal: Gd-diglycolate

Second-harmonic generation in the region of 8S 7/2 → 6I J ( J = 15/2, 13/2, 11/2, 9/2, 7/2) transitions in Gd 3+ ion in Gd-diglycolate (Na 3[Gd(C 4H 4O 5) 3]-2NaClO 4-6H 2O) crystal has been investigated, and at two-photon resonance, the role of the J-selection rule has been analysed.

Domain effects near the order-disorder and order-order ferromagnetic transitions in Gd and Dy

The technique of transient enhancement of the ac initial susceptibility χ has been used to compare domain effects in the ferromagnetic-paramagnetic transition of Gd and the ferromagnetic-antiferromagnetic transition of Dy. The temperature hysteresis in both χ and enhanced χ in the AF region of Dy indicates the existence of domains. The results for Dy support the suggestion that the transition from ferromagnetic to antiferromagnetic order upon warming in the vicinity of the Curie temperature takes place via an intermediate, moment-bearing domain structure.

Optical conductivity and direct interband transitions in Gd

Optical conductivity and direct interband transitions in Gd

Magnetic and superconducting transitions in GdxEr1−xRb4B4 and GdxY1−xRh4B4

The magnetic and superconducting transition temperatures and upper critical fields have been measured for GdxEr1−xRh4B4 and GdxY1−xRh4B4. The pressure dependence of Tc for the Er system for x?0.05 is 0.5×10−2 K/kbar. Both systems exhibit reentrant behavior, that is a superconducting transition followed by a magnetic transition at a lower temperature that destroys the superconductivity. For the Er system, the initial additions of Gd actually raise the superconducting critical field followed by the expected decrease for greater additions.

Ratio of electron capture to positron emission in the elementary-particle treatment of nuclearβdecay

Nuclear size effects and Coulomb corrections are included in the expression for the electron capture rate R/sub epsilon/ by using the ''elementary-particle'' approach of Armstrong and Kim. As an example, we use our result together with the corresponding expression for the positron emission rate R/sub ..beta../sup +/ to compute R/sub epsilon//R/sub ..beta pi.. for certain 1/2/sup +/ ..-->.. 1/2/sup +/ and 1/2/sup +/ ..-->.. 3/2/sup +/ transitions in Gd. Our ratios are in good agreement with conventional impulse-approximation calculations and, for a wide range of nuclear parameters, do not exhibit the anomalies seen experimentally.

Fluorescence spectra of Gd3+ions in CaO

Fluorescence lines corresponding to the 6P7/2 to 8S transitions of Gd3+ have been observed in CaO single crystals. Three main types of Gd3+ centre are identified in both as-received and annealed crystals, giving rise to lines at 315.27, 315.14 and 314.96 nm at 6K. At higher temperatures other lines appear corresponding to transitions from higher levels of the 6P7/2 multiplet. By measuring the intensity and lifetime of these lines all the transitions belonging to a given centre are grouped together, and the 314.96 nm line is shown to be due to a cubic Gd3+ centre. The 315.27 nm line is attributed to an orthorhombic centre by correlation with EPR results. Some results on ion-implanted samples are also presented, which show the presence of Gd3+ ions in some unusual sites, and also fluorescence from the 6I7/2 level.

The decay of 158Tb(150 y) to levels in 158Gd and 158Dy

The decay of 158Tb(150 y) to 158Gd and 158Dy has been studied with Ge(Li) detectors in singles and coincidence. The γ-ray transitions in Gd (total intensities in percent of total decays) are: 79.6 (80 %), 181.9 (12 %), 210.7 (0.01 %), 780.2 (10 %), 925.7 (0.05 %), 962.2 (20 %), 977.5 (0.16 %), 1107.7 (2.1 %) and 1187.2 keV (1.7 %). It was established with coincidence techniques that there are two transitions of the same energy (to within 0.5 keV) at 898 keV with intensities of 0.11 % and 0.17 %. Transitions in 158Dy are those of 99.0 (18 %) and 218.2 (1.1 %) keV. No evidence was obtained for a 720 keV transition in 158Dy reported by others. The previously reported levels at 79.6 (2 +), 261.5 (4 +), 1023.7 (2 −), 1041.8 (3 −) and 1187.2 (2 +) keV in 158Gd, and 99.0 (2 +) and 317.2 (4 +) keV in 158Dy were confirmed. In addition, the 1 − level at 977.5 keV in 158Gd is populated in the decay of 158Tb, and a new state (possibly 4 −) is established at 1159 keV using coincidence techniques. A K = 1 − band (1 − through 5 −) based at 977.5 keV is postulated and the results of a band-mixing calculation with a K = 0 − band are in fair agreement with the energy spacings and branching ratios. An improved coincidence experiment measuring the ratio of K- to L-electron capture and L- to total-electron capture for decay to the 1187.2 keV (2 +) level shows that the energy available for electron capture to the state is less than 54 keV but greater than the L-shell binding energy.

On the levels and transitions in Gd 155

Gamma-gamma coincidences of transitions in Gd 155 have been studied. The (45 keV gamma)—(60 keV gamma) angular correlation was measured and could be represented by W( θ) = 1+(0.155±0.016) P 2 (cos θ)+(0.028±0.025) P 4 (cos θ), which requires, together with the other properties of the 60 keV transition, 3 2 + assignment to the 105 keV level. This is identified with the 3 2 +[651] orbital in the Mottelson-Nilsson classification. The mixing ratio of the 45 keV transition is found to be δ 1 2 = M2/E1 = 0.0074 ( δ 1 = +0.086) with the mixing ratio of the 60 keV transition of δ 2 2 = E2/M1 = 0.04 ( δ 2 = −0.20±0.03). A level scheme based on these studies is presented and the properties of levels and transition are discussed.

On the levels and transitions in Gd 155

Gamma-gamma coincidences of transitions in Gd 155 have been studied. The (45 keV gamma)—(60 keV gamma) angular correlation was measured and could be represented by W( θ) = 1 + (0.155±0.016) P 2 (cos θ) + (0.028±0.025) P 4 (cos θ), which requires, together with the other properties of the 60 keV transition, 3 2 + assignment to the 105 keV level. This is identified with the 3 2 + [651] orbital in the Mottelson-Nilsson classification. The mixing ratio of the 45 keV transition is found to be δ 2 2 = M2 E1 = 0.0074 (δ 1 = +0.086) with the mixing ratio of the 60 keV transition of δ 2 2 = E2 M1 = 0.04 (δ 2 = −0.20±0.03) . A level scheme based on these studies is presented and the properties of levels and transitions are discussed.

Decay scheme of Tb 152

The decay scheme Tb 152→ Gd 152 has been investigated with sources prepared in an isotope separator. In addition to obtaining γ-ray and conversion electron spectra, γ-γ and e-γ coincidence measurements were carried out. A disintegration scheme has been established that includes all transitions in Gd 152 reported in earlier Eu 152 β-decay studies. In addition, four new transitions which establish two excited levels in Gd 152 were observed. One of these is a 0 + state at 1047 keV and the other, at 929 keV, has probably spin 2 +. The 0 + state decays with two monopole transitions to lower 0 + states, and the transition from the 929 keV level to the 344 keV first excited level, seems to contain a considerable E0 admixture. The two new levels are tentatively interpreted as members of a three-phonon quintet.