Precursor Nanoscale Textures: from Tweed to Glassy Behaviour

2011 ◽  
Vol 172-174 ◽  
pp. 135-143
Author(s):  
Antoni Planes ◽  
Pol Lloveras ◽  
Teresa Castán ◽  
Marcel Porta ◽  
Avadh Saxena
Keyword(s):  
Phase Transition ◽  
Mechanical Response ◽  
Elastic Anisotropy ◽  
Broad Temperature Range ◽  
Temperature Range ◽  
Spatially Inhomogeneous ◽  
Cluster Phase ◽  
Symmetry Structure ◽  
Nano Cluster ◽  
Low Symmetry

We study spatially inhomogeneous states that occur as precursors of marten-sitic/ferroelastic transitions. We will show that cross-hatched modulations (tweed patterns)arise at temperatures above the phase transition in the limit of high elastic anisotropy or lowdisorder while a nano-cluster phase-separated state occurs at low anisotropy or high disorder.In the latter case, nanoscale inhomogeneities give rise to glassy behaviour while the structuraltransition is inhibited. Interestingly, in this case the ferroelastic system also displays a largethermo-mechanical response so that the low symmetry structure can be easily induced by theapplication of relatively small stresses within a broad temperature range.

Preliminary Studies on the Dielectric Permittivity in the Isotropic and Mesophase of Cholesteryl Oleyl Carbonate

2002 ◽  
Vol 57 (3-4) ◽  
pp. 126-128 ◽  
Author(s):  
Sebastian Pawlus ◽  
Malgorzata Zasada ◽  
S. J. Rzoska
Keyword(s):  
Phase Transition ◽  
Dielectric Permittivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Broad Temperature Range ◽  
Phase Detection ◽  
Temperature Range ◽  
Simple Detection

The phase detection in cholesteryl oleyl carbonate was studied over a broad temperature range by dielectric spectroscopy. Tests were conducted in the static and the low frequency ionic regions. They point to the possibility of relatively simple detection of phase transition. Some manifestations of pretransitional behaviours were also found. - Pacs: 64.70Md, 77.22Ch, 64.30+t

Large electrocaloric effect over a wide temperature range in BaTiO3-modified lead-free ceramics

2019 ◽  
Vol 7 (5) ◽  
pp. 1353-1358 ◽  
Author(s):  
Luo Zhao ◽  
Xiaoqin Ke ◽  
Zhijian Zhou ◽  
Xiaoqi Liao ◽  
Junjie Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Wide Temperature Range ◽  
Diffuse Phase Transition ◽  
Lead Free ◽  
Broad Temperature Range ◽  
Electrocaloric Effect ◽  
Temperature Range ◽  
Lead Free Ceramics ◽  
Diffuse Phase

BT-13CH exhibits a large electrocaloric effect over a broad temperature range because of multiphase coexistence (MPC) with diffuse phase transition (DPT) character.

The distribution of minerals in hyper-agpaitic rocks in terms of symmetry: evolution of views on the number and symmetry of minerals

2001 ◽  
pp. 73-82 ◽  
Author(s):  
Alexander P. Khomyakov
Keyword(s):  
Crystal Structures ◽  
21St Century ◽  
Special Interest ◽  
Periodic Table ◽  
Mineral Species ◽  
Original Series ◽  
Temperature Range ◽  
The Earth ◽  
High Alkalinity ◽  
Low Symmetry

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Khomyakov, A. P. (2001). The distribution of minerals in hyper-agpaitic rocks in terms of symmetry: evolution of views on the number and symmetry of minerals. Geology of Greenland Survey Bulletin, 190, 73-82. https://doi.org/10.34194/ggub.v190.5176 _______________ Among the unique mineral localities of the Earth the complexes of nepheline syenites with hyper-agpaitic differentiates are of special interest due to their extreme diversity of mineral species. The four best studied complexes of this type – Khibina, Lovozero, Ilímaussaq and Mont Saint-Hilaire – have yielded more than 700 mineral species of which about 200 are new. The great mineral diversity is due to the combination of several factors, the most important of which is the extremely high alkalinity of agpaitic magmas, causing about half of the elements of the periodic table to be concentrated together. Minerals from hyper-agpaitic rocks are characterised by the predominance of highly ordered, low-symmetry crystal structures resulting, in particular, from the markedly extended temperature range of crystallisation. Generalisation of available data for unique mineral localities underpins the hypothesis that there is no natural limit to the number of mineral species. It is predicted that by the middle of the 21st century, the overall number of minerals recorded in nature will exceed 10 000, with the proportion of triclinic species increasing from the present 9% to 14.5%, and that of cubic species decreasing from 10% to 5%.

A passively mode-locked quantum-dot laser operating over a broad temperature range

2012 ◽  
Vol 101 (7) ◽  
pp. 071112 ◽  
Author(s):  
J. K. Mee ◽  
M. T. Crowley ◽  
N. Patel ◽  
D. Murrell ◽  
R. Raghunathan ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Broad Temperature Range ◽  
Temperature Range ◽  
Quantum Dot Laser

Nanowires self-assemble into β-MnO2 nanospheres to form crosslinking 3D hierarchical porous networks: with template-free fabrication and good supercapacitive performance over a broad temperature range

2021 ◽  
Vol 5 (19) ◽  
pp. 4944-4954
Author(s):  
Li-Li Yu ◽  
Wei-Ling Xu ◽  
Jian-Guo Zhang ◽  
Shuang Li ◽  
Rong-Bing Li ◽  
...  
Keyword(s):  
Broad Temperature Range ◽  
Supercapacitive Performance ◽  
Temperature Range ◽  
Porous Networks ◽  
Self Assembling ◽  
Hierarchical Porous ◽  
Template Free

Template-free fabrication of nanowires self-assembling into nanospheres and crosslinking into 3D hierarchical porous β-MnO2 networks with good supercapacitive performance over a broad temperature range.

Cluster phase transition in insulating spin glass Ga0.4Fe0.6NiAlO4

1992 ◽  
Vol 68 (1-4) ◽  
pp. 279-282 ◽  
Author(s):  
J. K. Srivastava ◽  
J. Ferreirinho ◽  
S. Ramakrishnan ◽  
S. J. Campbell ◽  
G. Chandra ◽  
...  
Keyword(s):  
Phase Transition ◽  
Spin Glass ◽  
Cluster Phase

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

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