Observation of a magnetic-field-induced resonance in the homogeneous dephasing time for the1D2−3H4transition inPr3+:YAlO3 (original) (raw)
Related papers
Influence of excited-statePr3+on the relaxation of thePr3+:YAlO33H4−1D2transition
Physical Review B, 1991
Two-pulse photon-echo measurements on the 0.1 at. % Pr'+:YA10, H4-'D& transition suggest that the relaxation time depends on the density of excited states created by the excitation pulses. The dependence of the relaxation time on the intensity of each excitation pulse shows that our results are inconsistent with instantaneous spectral diffusion, a model often invoked in this type of experiment, where excited states created by the second pulse chiefly inhuence the relaxation time. A homogeneous linewidth contribution, noted in previous work as being of unknown origin, is eliminated at low excitation fluences.
Optically detected nuclear resonance of excited and ground states of YPO4:Pr3+
Optics Communications, 1984
The hyperfine structure and nuclear magnetic moments of Pr 3+ : YPO4 in the ground state and lowest component of the 1 D¢2 excited state have been measured using laser holeburning and optically detected nuclear resonance. For the ground state, the quadrupole coupling constants are D g = 3.079 MHz, r~ < 0.01 and the magnetic splitting factors "r~!2~r = 2.308 kHz/G, 3,g[2~r = 5.41 kHz/G. The corresponding excited state values are D e = 2.272 MHz, n < 0.002 and ~/~ ~2~r = 1.42 kHz /G,-r~./2~r = 1.72 kHz/G. Model calculations of the splitting factors assuming pure 4f 2 electron states agree well with the ground state values but rather poorly with those in the excited state.
First-order magnetic phase transition in Pr2In with negligible thermomagnetic hysteresis
Physical Review B, 2020
Magnetic first-order phase transitions are key for the emergence of functionalities of fundamental and applied significance, including magnetic shape memory as well as magnetostrictive and magnetocaloric effects. Such transitions are usually associated with thermomagnetic hysteresis. We report the observation of a firstorder transition in Pr 2 In from a paramagnetic to a ferromagnetic state at T C = 57 K without a detectable thermomagnetic hysteresis, which is also accompanied by a large magnetocaloric effect. The peculiar electronic structure of Pr 2 In exhibiting a large density of states near the Fermi energy explains the highly responsive magnetic behavior of the material. The magnetic properties of Pr 2 In are reported, including observation of another (second-order) magnetic transition at 35 K.
Homogeneous broadening and hyperfine structure of optical transitions inPr3+:Y2SiO5
Physical Review B, 1995
Contributions to the homogeneous linewidth of the H&(1)~'Dz(1) transition for the two crystallographic sites of Pr in Y2SiO, have been investigated using photon echoes. The effects of excitationintensity-dependent dephasing or instantaneous diffusion were systematically studied to allow accurate determination of the optical resonance widths. Homogeneous linewidths of 2.8 kHz (site 1) and 1 kHz (site 2) were measured with no applied magnetic field and with sufficiently low laser intensity to minimize the effects of instantaneous diffusion. Using the same excitation intensity, widths of 2.1 kHz (site 1) and 0.85 kHz (site 2) were obtained with an applied magnetic field of 77 G, demonstrating a significant contribution of Y nuclear-spin fluctuations to the zero-field homogeneous linewidth. Extrapolation to zero excitation intensity yielded optical resonance widths that were only slightly narrower than the measured values. Optically detected nuclear magnetic resonance measurements determined the hyperfine structure of the H& ground state for each site; the hyperfine levels of the lowest component of the 'D2 manifold for each site were determined using photon echo nuclear double resonance. The relatively large oscillator strength of 3 X 10 for a rare-earth ion, in conjunction with long dephasing times makes this material a useful candidate for demonstration of time-domain signal processing and optical data storage.
Magnetic transitions in Pr2NiO4 single crystal
Journal of Applied Physics, 1991
The magnetic properties of a stoichiometric PrzNi04 single crystal have been examined by means of the temperature dependence of the complex ac susceptibility and the isothermal magnetization in fields up to 200 kOe at T = 4.2 K. Three separate phases have been identified' and their anisotropic character has been analyzed. A collinear antiferromagnetic phase appears first between TN = 325 K and T,, = 115 K, where the Pr ions are polarized by an internal magnetic field. At T,, a first modification of the magnetic structure occurs in parallel with a structural phase transition (Bmab to P4$ncm). This magnetic transition has a first-order character and involves both the out-of-plane and the in-plane spin components (magnetic modes g, and g#Jn respectively). A second magnetic transition having also a first-order character is also clearly identified at Tc2 = 90 K which corresponds to a spin reorientation process (g&,JZ to cxgvaZ magnetic modes). It should be noted as well that the out-of-phase component of x== shows a peak around 30 K which reflects the coexistence of both magnetic configurations in a wide temperature interval. Finally, two field-induced transitions have been observed at 4.2 K when the field is directed along the c axis. We propose that the high-field anomaly arises from a metamagnetic transition of the weak ferromagnetic component, similarly to La$uOe
Journal of Applied Physics
The structural and magnetic properties of Y 0.9 Pr 0.1 Fe 2 D 3.5 deuteride have been investigated by synchrotron and neutron diffraction, magnetic measurements, and differential scanning calorimetry. Deuterium insertion induces a 23.5% cell volume increase and a lowering of crystal symmetry compared to the cubic C15 Y 0.9 Pr 0.1 Fe 2 parent compound (Fd-3m SG). The deuteride is monoclinic (P2 1 /c SG) below 330 K and undergoes a first-order transition between 330 and 350 K toward a pseudo-cubic structure (R-3 m SG) with T O-D = 342(2) K. In both structures, the D atoms are located in 96% R 2 Fe 2 and 4% RFe 3 tetrahedral interstitial sites (R = Y 0.9 Pr 0.1). The compound is ferromagnetic, accompanied by a magnetostrictive effect below T C = 274 K. The analysis of the critical exponents indicates a second-order type transition with a deviation from the isotropic 3D Heisenberg model toward the 3D XY model. This implies an easy plane of magnetization in agreement with cell parameter variation showing planar magnetic orientation. A weak magnetic peak is even observed at the order-disorder transition with a maximum at 343 K. Magnetic entropy variations are characteristic of direct and inverse magnetocaloric effects at T C and T O-D , respectively.
OPTICAL DEPHASING OF Pr 3+ IONS BY NONEQUILIBRIUM PHONONS IN LaF 3 AND YAlO 3
Le Journal de Physique Colloques, 1985
We describe a new effect, phonon-induced coherence loss (PICOLO), whereby a monoenergetic nonequilibrium phonon distribution is responsible for the loss of optical coherence. The interaction of these phonons with the ions is monitored with the free induction decay or photon echo. We show how PICOLO can be used to study the electron-phonon interaction and the dynamics of phonons.
The influence of the spin reorientation process on the magnetocaloric effect: Application to PrAl2
Journal of Magnetism and Magnetic Materials, 2007
In this work we report a theoretical investigation about the influence of the spin reorientation on the magnetic and magnetocaloric properties of PrAl 2. The model Hamiltonian takes into account the exchange magnetic interaction and the crystalline electrical field anisotropy. All theoretical results were obtained using the proper model parameters found in the literature for this compound. An anomalous valley was predicted to exist in the magnetocaloric curves for magnetic field changes along /1 1 1S non easy magnetic crystallographic direction. This anomaly was ascribed to the spin reorientation process.