scholarly journals RKKY interactions and magnetic structure of rare-earth quasicrystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C84-C84
Author(s):  
Stefanie Thiem
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Magnetic Moments ◽  
Temperature Phase ◽  
Strongly Coupled ◽  
Cluster Spin Glass ◽  
Experimental Findings ◽  
Low Temperature Phase ◽  
Quasiperiodic Tilings ◽  
Good Agreement

We study the structure of the RKKY interactions and the corresponding low-temperature behaviour of magnetic moments for quasiperiodic tilings. The alignment of magnetic moments in rare-earth quasicrystals remains a fundamental open problem despite the continuous effort since the discovery of this material class. We compute the RKKY interactions between the localized magnetic moments by means of a continued fraction expansion of the Green's function of the conduction electrons. Thus, our approach takes the structure of the critical electronic wave functions into account. The results show the emergence of strongly coupled spin clusters while the inter-cluster coupling is significantly weaker. Monte Carlo simulations reveal with decreasing temperature first the freezing of spins within the clusters followed by the freezing of the clusters. Thus, the low-temperature phase behaves has similarities to a cluster spin glass which is in good agreement with previous experimental findings.

Low-temperature phase transitions in the rare-earth ferroborate Nd0.75Dy0.25Fe3(BO3)4

2010 ◽  
Vol 36 (3) ◽  
pp. 279-281 ◽  
Author(s):  
G. A. Zvyagina ◽  
K. R. Zhekov ◽  
I. V. Bilych ◽  
A. A. Zvyagin ◽  
L. N. Bezmaternyhk ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase Transitions ◽  
Low Temperature ◽  
Temperature Phase ◽  
Low Temperature Phase ◽  
The Rare Earth

Superconductivity and Magnetic Order: Low Temperature Phase Diagrams

1982 ◽  
Vol 19 ◽  
Author(s):  
M. Brian Maple
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Phase Diagrams ◽  
Critical Magnetic Field ◽  
Magnetic Interactions ◽  
Antiferromagnetic Order ◽  
Temperature Phase ◽  
Field Versus ◽  
Ferromagnetic Interactions ◽  
Low Temperature Phase

ABSTRACTRecent experiments on magnetically-ordered ternary and pseudoternary rare earth superconductors are briefly reviewed. Superconductivity has been found to coexist with antiferromagnetic order, but to be destroyed by the onset of ferromagnetic order at a second transition temperature Tc2∼TM, where TM is the Curie temperature. In antiferromagnetic superconductors, the antiferromagnetic order modifies superconducting properties such as the curve of the upper critical magnetic field versus temperature. In ferromagnetic superconductors, a long wavelength (∼ 102 Å sinusoidally modulated magnetic state develops in the superconducting state as a result of the superconducting-ferromagnetic interactions. The interplay of superconductivity and competing magnetic interactions in pseudoternary rare earth systems produces complex and interesting low temperature phase diagrams.

The Nematic Character of a Hidden Ordered State revealed by Magnetic Fields.

2014 ◽  
Vol 1683 ◽  
Author(s):  
Peter S. Riseborough ◽  
S. G. Magalhaes ◽  
E.J. Calegari
Keyword(s):  
Magnetic Field ◽  
Critical Temperature ◽  
Low Temperature ◽  
Applied Field ◽  
Temperature Phase ◽  
Spin Quantization ◽  
Experimental Findings ◽  
Low Temperature Phase ◽  
The Magnetic Field ◽  
Ordered State

ABSTRACTWe examine a novel phase of the underscreened Anderson lattice Model that might pertain to the ”Hidden Ordered” phase of URu2Si2. We show that the system breaks spin-rotational invariance below the critical temperature and spontaneously selects a preferred axis of spin quantization. As a result, the low temperature phase exhibits a magnetic anisotropy, where the electronic properties depend not only on the magnitude of the magnetic field but also on the orientation of the applied field relative to the axis of quantization. The results are discussed in the context of recent experimental findings on URu2Si2.

scholarly journals LOW TEMPERATURE PHASE OF THE RARE-EARTH-FREE MnBi MAGNETIC MATERIAL

2018 ◽  
Vol 54 (1A) ◽  
pp. 50
Author(s):  
Nguyen Van Vuong
Keyword(s):  
Magnetic Material ◽  
Phase Diagram ◽  
Rare Earth ◽  
Low Temperature ◽  
Temperature Gradient ◽  
Diffusion Mechanism ◽  
Time Dependent ◽  
Temperature Phase ◽  
Low Temperature Phase ◽  
The Rare Earth

The Low Temperature Phase (LTP) content determines the spontaneous magnetization Ms of the rare-earth-free hard magnetic material MnBi. LTP in MnBi samples alloyed by the arc-melting is timely developed when they are annealed at the annealing temperatures Ta < 340 oC. Because of the complexity of the phase diagram of MnxBi(100-x) system, the content hardly reaches the value of 100 wt%. Based on the phase diagram of MnxBi(100-x) system, the upper limit * was calculated and 59.8 wt% is the highest content which can be reached when the alloy is isothermally annealed for a long time. The time-dependent behavior of (t) reveals that the LTP is formed from Mn and Bi phases by the diffusion mechanism. The time-dependent diffusion equation has been used to investigate the diffusion process between Mn and Bi in order to form the LTP. The comparison between the theoretical and experimental data allowed to estimate the mutual diffusion coefficient D 510-12 cm2/s. This small value of D is suggested due to not only the low value of Ta necessary for forming LTP but the high surface tension of Bi melted at Ta as well. The calculated results showed that the size distribution of Mn grains embedded in the Bi matrix affected the dependence (t), enhancing and inhibiting in the samples annealed for short and long times, respectively. To increase over *, the anneal at Ta superimposed by the small temperature gradient of 2 oC/cm has been performed. This temperature-gradient driven annealing technique helped to overcome * and reach the value of 83 wt% which corresponds to the Ms = 60 emu/g measured at the field strength of 4 Tesla.

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