Spatially Random Heisenberg Spins at Very Low Temperatures. II. Dilute Antiferromagnet with Nearest-Neighbor Substitutional Short-Range Order

1972 ◽  
Vol 6 (7) ◽  
pp. 2826-2837 ◽  
Author(s):  
Raza A. Tahir-Kheli
Keyword(s):  
Low Temperatures ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order

scholarly journals Magnetically driven short-range order can explain anomalous measurements in CrCoNi

2021 ◽  
Vol 118 (13) ◽  
pp. e2020540118
Author(s):  
Flynn Walsh ◽  
Mark Asta ◽  
Robert O. Ritchie
Keyword(s):  
First Principles ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order ◽  
Magnetic Interactions ◽  
First Principles Calculations ◽  
Principal Element ◽  
The Impact ◽  
Magnetically Aligned

The presence, nature, and impact of chemical short-range order in the multi-principal element alloy CrCoNi are all topics of current interest and debate. First-principles calculations reveal that its origins are fundamentally magnetic, involving repulsion between like-spin Co–Cr and Cr–Cr pairs that is complemented by the formation of a magnetically aligned sublattice of second-nearest-neighbor Cr atoms. Ordering models following these principles are found to predict otherwise anomalous experimental measurements concerning both magnetization and atomic volumes across a range of compositions. In addition to demonstrating the impact of magnetic interactions and resulting chemical rearrangement, the possible explanation of experiments would imply that short-range order of this type is far more prevalent than previously realized.

Relation Between the Chemical Short-Range Order in Liquid and Amorphous Alloys

1981 ◽  
Vol 8 ◽  
Author(s):  
C.N.J. Wagneri ◽  
H. Ruppersberg
Keyword(s):  
Amorphous Alloys ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Diffraction Theory ◽  
Range Order ◽  
Glassy Alloys ◽  
Structure Factors ◽  
Partial Interference

ABSTRACTRecent advances in both diffraction theory and experiment have led to the determination of the topological and chemical short-range order in liquid alloys and metallic glasses. In binary alloys, three partial interference functions (or partial structure factors) must be determined to evaluate the Warren chemical short-range order parameter α. Examples of recent attempts to determine α in binary liquid and glassy alloys are given. In most glasses, studied so far, evidence exists for the occurrence of unlike nearest neighbor ordering which must be present in the liquid state.

Fluctuation Microscopy: A New Class of Microscopy Techniques for Probing Medium Range Order in Amorphous Materials

1998 ◽  
Vol 4 (S2) ◽  
pp. 702-703
Author(s):  
J. M. Gibson ◽  
M. M. J. Treacy ◽  
P. M. Voyles
Keyword(s):  
Long Range ◽  
Short Range ◽  
Amorphous Materials ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order ◽  
Regular Tetrahedron ◽  
Long Range Order ◽  
Medium Range Order ◽  
Medium Range

Amorphous materials are devoid of periodic long range order, but at the nearest-neighbor level they possess a high degree of short-range order. In amorphous tetrahedral semiconductors, such as Si and Ge, this short-range order arises because each atom attempts to satisfy four bonds arranged as a regular tetrahedron. It is the rotations about each bond, from the second-nearest-neighbor outwards, that result in the loss of long-range order. It is apparent from modeling of amorphous materials, that there is considerable flexibility as to how rapidly the medium-range-order diminishes. The continuous random network (CRN) is a hypothetical tetrahedral extended structure wherein the atoms possess full four-connected coordination, but have minimal medium-range order. However, real amorphous materials infrequently exhibit true CRN-like topologies. Traditionally, diffraction has been used to study short- and medium-range order in amorphous materials. Assuming kinematical scattering, and that every atom has a similar environment, a radial distribution function (RDF) can be extracted which is sensitive only to the averaged atom pair-correlations out to ∼1 nm.

Short Range Structure of Amorphous Ni50Ta50-Alloys by Means of X-Ray- and Neutron-Diffraction

1992 ◽  
Vol 47 (7-8) ◽  
pp. 826-832 ◽  
Author(s):  
H. Uhlig ◽  
L. Rohr ◽  
H.-J. Güntherodt ◽  
P. Fischer ◽  
P. Lamparter ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order ◽  
Partial Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
Binding Behavior ◽  
Structure Factors

Abstract Amorphous Ni50Ta50-samples with their high crystallization temperature of 985 K were investigated. To evaluate the three partial structure factors of amorphous Ni50Ta50 one X-ray diffraction experiment was performed with Ni50Ta50 and two neutron diffraction experiments with Co10Ni40Ta50 and with Ni50Ta50, respectively. The Bhatia-Thornton partial structure factor SCC(Q) indicates rather strong chemical short range order which also explains the premaximum observed in the Faber-Ziman partial SNiNi(Q)-function. The nearest neighbor distance is 2.82 Å for Ni-Ni, 2.91 Å for Ta-Ta, and is shortest for Ni-Ta, 2.44 Å. The coordination numbers are NNiNi = 4.9, NTaTa = 8.2, and NNiTa = 6.0. We report on the chemical short range order and the possible binding behavior in a-Ni50Ta50 and compare the present results with those reported in the literature on a-Ni40Ti60 as well as on a-Ni55Ta45

Range of order in antiferromagnets with next-nearest neighbor coupling

1970 ◽  
Vol 48 (18) ◽  
pp. 2118-2122 ◽  
Author(s):  
John Stephenson
Keyword(s):  
Neutron Diffraction ◽  
Wide Class ◽  
Short Range ◽  
Short Range Order ◽  
Nearest Neighbor ◽  
Range Order ◽  
Two Dimensional ◽  
General Argument ◽  
Nearest Neighbor Coupling

A general argument is presented that a change in the nature of the short-range order will occur above a precisely located temperature TD, the disorder point, for a wide class of magnetic models. The range of order is calculated exactly for two-dimensional asymmetric Ising triangular and union-jack lattices. A sharp cusp in the range of order vs. temperature graph occurs at the disorder point. It is proposed that measurements of the range of order by neutron-diffraction techniques be made on suitable antiferromagnetic crystals to determine whether a disorder point can be detected. It is suggested that two-dimensional antiferromagnets, such as manganese formate dihydrate, may exhibit disorder points.

Sign in / Sign up

Export Citation Format

Share Document