ChemInform Abstract: Phase Transitions and Crystal-Field Levels in Nd2NiO4.

ChemInform ◽  
2010 ◽  
Vol 27 (14) ◽  
pp. no-no
Author(s):  
M. CASTRO ◽  
R. BURRIEL
Keyword(s):  
Phase Transitions ◽  
Crystal Field

Magnetic properties of the mixed spin-5/2 and spin-3/2 Blume-Capel Ising system on the two-fold Cayley tree

Open Physics ◽  
2009 ◽  
Vol 7 (3) ◽  
Author(s):  
Rachidi Yessoufou ◽  
Saliou Amoussa ◽  
Felix Hontinfinde
Keyword(s):  
Magnetic Properties ◽  
Phase Transitions ◽  
Crystal Field ◽  
Cayley Tree ◽  
Second Order ◽  
Coordination Numbers ◽  
First Order ◽  
Mixed Spin ◽  
Second Order Transition ◽  
Zero Values

AbstractWe use exact recursion relations to study the magnetic properties of the half-integer mixed spin-5/2 and spin-3/2 Blume-Capel Ising ferromagnetic system on the two-fold Cayley tree that consists of two sublattices A and B. Two positive crystal-field interactions Δ1 and Δ2 are considered for the sublattice with spin-5/2 and spin-3/2 respectively. For different coordination numbers q of the Cayley tree sites, the phase diagrams of the model are presented with a special emphasis on the case q = 3, since other values of q reproduce similar results. First, the T = 0 phase diagram is illustrated in the (D A = Δ1/J,D B = Δ2/J) plane of reduced crystal-field interactions. This diagram shows triple points and coexistence lines between thermodynamically stable phases. Secondly, the thermal variation of the magnetization belonging to each sublattice for some coordination numbers q are investigated as well as the Helmoltz free energy of the system. First-order and second-order phase transitions are found. The second-order phase transitions become sharper and sharper when D A or D B increases. The first-order transitions only exist for some appropriate non-zero values of D A and/or D B. The corresponding transition lines never connect to the second-order transition lines. Thus, the non-existence of tricritical points remains one of the key features of the present model. The magnetic exponent β 0 of the model is estimated and found to be ¼ at small values of D A = D B = D and β 0 = ½ at large values of D. At intermediate values of D, there is a crossover region where the magnetic exponent displays interesting behaviours.

Effect of a crystal field on phase transitions in a spin-1 transverse Ising model

1993 ◽  
Vol 47 (2) ◽  
pp. 827-830 ◽  
Author(s):  
Xue-Fan Jiang ◽  
Jia-Liang Li ◽  
Jia-lin Zhong ◽  
Chuan-Zhang Yang
Keyword(s):  
Phase Transitions ◽  
Ising Model ◽  
Crystal Field ◽  
Transverse Ising Model

A new model for the crystal field and the quadrupolar phase transitions of UPd3

2003 ◽  
Vol 15 (28) ◽  
pp. S1923-S1935 ◽  
Author(s):  
K A McEwen ◽  
J-G Park ◽  
A J Gipson ◽  
G A Gehring
Keyword(s):  
Phase Transitions ◽  
Crystal Field ◽  
New Model

THE CRYSTAL FIELD EFFECTS ON THE PHASE DIAGRAMS OF THE SPIN-2 BILAYER BETHE LATTICE

2008 ◽  
Vol 22 (27) ◽  
pp. 4877-4898 ◽  
Author(s):  
ERHAN ALBAYRAK ◽  
SEYMA AKKAYA ◽  
SABAN YILMAZ
Keyword(s):  
Phase Transitions ◽  
Phase Diagrams ◽  
Crystal Field ◽  
Ground State ◽  
Bethe Lattice ◽  
Interlayer Coupling ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Temperature Dependent ◽  
Field Interaction

The bilayer spin-2 Ising model on the Bethe lattice is investigated by taking into account the intralayer coupling constants of the two layers J1 and J2, interlayer coupling constant between the layers J3 and crystal field interaction Δ by using the exact recursion equations in a pairwise approach. The ground state (GS) phase diagrams of the model are obtained on the (J2/|J1|, J3/q|J1|) planes for given Δ values and on the (Δ/qJ, J3/qJ) plane when J1 = J2 = J, and thus 33 distinct GS configurations are found. The temperature-dependent phase diagrams are obtained for J1 > 0, J2 > 0, and for J3 > 0 or J3 < 0 on the (kT/J1, J3/J1) planes for given Δ/qJ1 and J2/J1 and on the (Δ/J, kT/J) plane for given J3/J when J1 = J2 = J for the coordination number q = 3. It was found that the system exhibits both first- and second-order phase transitions and tricritical points. The paramagnetic phases are also classified by studying the thermal variations of the quadrupolar moments.

Phase transitions of Ising mixed spin 1 and 3/2 with random crystal field distribution

2016 ◽  
Vol 460 ◽  
pp. 210-221 ◽  
Author(s):  
S. Sabri ◽  
M. EL Falaki ◽  
M. EL Yadari ◽  
A. Benyoussef ◽  
A. EL Kenz
Keyword(s):  
Phase Transitions ◽  
Crystal Field ◽  
Field Distribution ◽  
Mixed Spin

Magnetic phase transitions and crystal-field splitting inK2UX5(X=Cl,Br,I)

1995 ◽  
Vol 51 (5) ◽  
pp. 2881-2890 ◽  
Author(s):  
L. Keller ◽  
A. Furrer ◽  
P. Fischer ◽  
P. Allenspach ◽  
K. Krämer ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Crystal Field ◽  
Magnetic Phase ◽  
Crystal Field Splitting ◽  
Magnetic Phase Transitions ◽  
Field Splitting

scholarly journals Optical spectroscopy of ErFe3(BO3)4: detection of phase transitions and crystal-field levels of the Er3+ ground multiplet

2018 ◽  
Vol 185 ◽  
pp. 07002 ◽  
Author(s):  
Dmitry Erofeev ◽  
Artjoms Jablunovskis ◽  
Elena Chukalina
Keyword(s):  
Phase Transitions ◽  
Single Crystals ◽  
Crystal Field ◽  
Phonon Mode ◽  
Structural Phase ◽  
Exchange Splitting ◽  
Temperature Behaviour ◽  
Interference Band ◽  
Ground Multiplet ◽  
Ordered State

High-resolution spectra of oriented ErFe3(BO3)4 single crystals are registered in the spectral range 500 – 8000 cm-1 at various temperatures (4 – 470 K). The temperature behaviour of the phonon mode at 976 cm-1 allowed us to register a structural phase transition at TS=431 K. The energies of crystal-field levels of the ground 4I15/2 and the first excited 4I13/2 multiplets of the Er3+ ion are determined in the paramagnetic state of ErFe3(BO3)4. The exchange splitting of the ground Kramers doublet in the magnetically ordered state was found to be Δ0=6.3±1 cm-1. The interference occurring due to birefringence in the single crystals was also registered. The temperature dependence of the position of the maximum of the interference band demonstrates two anomalies, at TN and TS, associated with the phase transitions in ErFe3(BO3)4.

Phase Transitions and Spin Relaxation in La0.95Sr0.05MnO3

2003 ◽  
Vol 17 (10n12) ◽  
pp. 459-467 ◽  
Author(s):  
B. I. Kochelaev ◽  
E. Shilova ◽  
J. Deisenhofer ◽  
H.-A. Krug von Nidda ◽  
A. Loidl ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Model Calculation ◽  
Crystal Field ◽  
Spin Relaxation ◽  
Paramagnetic Resonance ◽  
Resonance Linewidth ◽  
Teller Transition ◽  
Jahn Teller

We present a model calculation of the paramagnetic-resonance linewidth in La 0.95 Sr 0.05 MnO 3. Both the temperature and the angular dependencies can be described by contributions from the crystal field due to the cooperative Jahn–Teller transition.

Sign in / Sign up

Export Citation Format

Share Document