1,960 research outputs found
The effects of cold rolling on the notched and unnotched tensile properties of type 310 stainless steel at plus 75 deg F, minus 320 deg F and minus 423 deg F
Effects of cold rolling on notched and unnotched tensile properties of type 310 stainless stee
Charge modulations vs. strain waves in resonant x-ray scattering
A method is described for using resonant x-ray scattering to separately
quantify the charge (valence) modulation and the strain wave associated with a
charge density wave. The essence of the method is a separation of the atomic
form factor into a "raw" amplitude, fR(w), and a valence-dependent amplitude,
fD(w), which in many cases may be determined independently from absorption
measurements. The advantage of this separation is that the strain wave follows
the quantity |fR(w) + fD(w)|^2 whereas the charge modulation follows only
|fD(w)|^2. This allows the two distinct modulations to be quantified
separately. A scheme for characterizing a given CDW as Peierls-like or
Wigner-like naturally follows. The method is illustrated for an idealized model
of a one-dimensional chain.Comment: 6 pages, 4 figure
Anisotropic electron spin resonance of YbIr2Si2
A series of electron spin resonance (ESR) experiments were performed on a
single crystal of the heavy fermion metal YbIr2Si2 to map out the anisotropy of
the ESR-intensity I_ESR which is governed by the microwave field component of
the g-factor. The temperature dependencies of I_ESR(T) and g(T) were measured
for different orientations and compared within the range 2.6K \le T \le 16K.
The analysis of the intensity dependence on the crystal orientation with
respect to both the direction of the microwave field and the static magnetic
field revealed remarkable features: The intensity variation with respect to the
direction of the microwave field was found to be one order of magnitude smaller
than expected from the g-factor anisotropy. Furthermore, we observed a weak
basal plane anisotropy of the ESR parameters which we interpret to be an
intrinsic sample property.Comment: 10 pages, 5 figure
Pressure Induced Hydration Dynamics of Membranes
Pressure-jump initiated time-resolved x-ray diffraction studies of dynamics
of the hydration of the hexagonal phase in biological membranes show that (i)
the relaxation of the unit cell spacing is non-exponential in time; (ii) the
Bragg peaks shift smoothly to their final positions without significant
broadening or loss in crystalline order. This suggests that the hydration is
not diffusion limited but occurs via a rather homogeneous swelling of the whole
lattice, described by power law kinetics with an exponent .Comment: REVTEX 3, 10 pages,3 figures(available on request),#
Electron Spin Resonance of the Yb 4f moment in Yb(Rh1-xCox)2Si2
[published in Phys. Rev. B 85, 035119 (2012)] The evolution of spin dynamics
from the quantum critical system YbRh2Si2 to the stable trivalent Yb system
YbCo2Si2 was investigated by Electron Spin Resonance (ESR) spectroscopy. While
the Kondo temperature changes by one order of magnitude, all compositions of
the single crystalline series Yb(Rh1-xCox)2Si2 show well defined ESR spectra
with a clear Yb3+ character for temperatures below \approx 20 K. With
increasing Co-content the ESR g-factor along the c-direction strongly increases
indicating a continuous change of the ground state wave function and, thus, a
continuous change of the crystal electric field. The linewidth presents a
complex dependence on the Co-content and is discussed in terms of the Co-doping
dependence of the Kondo interaction, the magnetic anisotropy and the influence
of ferromagnetic correlations between the 4f states. The results provide
evidence that, for low Co-doping, the Kondo interaction allows narrow ESR
spectra despite the presence of a large magnetic anisotropy, whereas at high
Co-concentrations, the linewidth is controlled by ferromagnetic correlations. A
pronounced broadening due to critical correlations at low temperatures is only
observed at the highest Co-content. This might be related to the presence of
incommensurate magnetic fluctuations.Comment: 8 pages, 8 Figure
Comparative analysis of acoustic testing techniques, exhibit A Final report
Calculation methods for vibration responses of spacecraft structural members to acoustic field
New Perspectives on Kristallnacht: After 80 Years, the Nazi Pogrom in Global Comparison
On November 9 and 10, 1938, Nazi leadership unleashed an unprecedented orchestrated wave of violence against Jews in Germany, Austria, and the Sudetenland, supposedly in response to the assassination of a Nazi diplomat by a young Polish Jew, but in reality to force the remaining Jews out of the country. During the pogrom, Stormtroopers, Hitler Youth, and ordinary Germans murdered more than a hundred Jews (many more committed suicide) and ransacked and destroyed thousands of Jewish institutions, synagogues, shops, and homes. Thirty thousand Jews were arrested and sent to Nazi concentration camps.
Volume 17 of the Casden Annual Review includes a series of articles presented at an international conference titled “New Perspectives on Kristallnacht: After 80 Years, the Nazi Pogrom in Global Comparison.” Assessing events 80 years after the violent anti-Jewish pogrom of 1938, contributors to this volume offer new cutting-edge scholarship on the event and its repercussions. Contributors include scholars from the United States, Germany, Israel, and the United Kingdom who represent a wide variety of disciplines, including history, political science, and Jewish and media studies. Their essays discuss reactions to the pogrom by victims and witnesses inside Nazi Germany as well as by foreign journalists, diplomats, Jewish organizations, and Jewish print media. Several contributors to the volume analyze postwar narratives of and global comparisons to Kristallnacht, with the aim of situating this anti-Jewish pogrom in its historical context, as well as its place in world history.https://docs.lib.purdue.edu/purduepress_previews/1042/thumbnail.jp
Spin fluctuations with two-dimensional XY behavior in a frustrated S = 1/2 square-lattice ferromagnet
The spin dynamics of the layered square-lattice vanadate Pb2VO(PO4)2 is
investigated by electron spin resonance at various magnetic fields and at
temperatures above magnetic ordering. The linewidth divergence towards low
temperatures seems to agree with isotropic Heisenberg-type spin exchange
suggesting that the spin relaxation in this quasi-two dimensional compound is
governed by low-dimensional quantum fluctuations. However, a weak easy- plane
anisotropy of the g factor points to the presence of a planar XY type of
exchange. Indeed, we found that the linewidth divergence is described best by
XY-like spin fluctuations which requires a single parameter only. Therefore,
ESR-probed spin dynamics could establish Pb2VO(PO4)2 as the first frustrated
square lattice system with XY-inherent spin topological fluctuations.Comment: 5 pages, 3 figure
Sum Rules and Ward Identities in the Kondo Lattice
We derive a generalized Luttinger-Ward expression for the Free energy of a
many body system involving a constrained Hilbert space. In the large limit,
we are able to explicity write the entropy as a functional of the Green's
functions. Using this method we obtain a Luttinger sum rule for the Kondo
lattice. One of the fascinating aspects of the sum rule, is that it contains
two components, one describing the heavy electron Fermi surface, the other, a
sea of oppositely charged, spinless fermions. In the heavy electron state, this
sea of spinless fermions is completely filled and the electron Fermi surface
expands by one electron per unit cell to compensate the positively charged
background, forming a ``large'' Fermi surface. Arbitrarily weak magnetism
causes the spinless Fermi sea to annihilate with part of the Fermi sea of the
conduction electrons, leading to a small Fermi surface. Our results thus enable
us to show that the Fermi surface volume contracts from a large, to a small
volume at a quantum critical point. However, the sum rules also permit the
possible formation of a new phase, sandwiched between the antiferromagnet and
the heavy electron phase, where the charged spinless fermions develop a true
Fermi surface.Comment: 24 pages, 4 figures. Version two contains a proof of the "Entropy
formula" which connects the entropy directly to the Green's functions.
Version three contains corrections to typos and a more extensive discussion
of the physics at finite
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