165 research outputs found
Striving towards gender equality in education The role of Bernice Sandler
This qualitative study examines why Bernice Sandler's role was significant in achieving gender equality in education, and the role she played in the enactment of Title IX legislation, which changed the face of American education. A historical overview of the development of women's higher education is provided and evaluated in order to describe the context of gender discrimination. Gender has been an important tool of oppression of women for centuries. In that aspect, no country has been an exception, including the United States. Like everywhere else, in America as well, the socio-cultural norms and gender roles expectations hindered women from achieving a full education. The potential barriers to women's higher education, as well as the potential outcomes of these marginalizations, were explored in order to gain a more in-depth understanding of this study. Women faced innumerable socially constructed barriers that constrained their educational development. Women's proper role was considered to be a mother, and her proper place was the home. Everything else was considered beyond the normal gender role definitions. But fortunately, there were few early voices that propagated the idea of the importance of giving higher education for women. As a result, women's higher education has gone through various forms, and types of institutions. Female seminaries, women's colleges, co-education and so on, before it spread to all colleges and universities. Even though by the middle of the twentieth century, women have gained broader access to education, but in certain areas, discrimination was still rampant. For example, especially in medicine, law, and business women's entry was restricted through various measures, such as the quota system, which used to limit the number of women being admitted. In the academic workplace, female faculties were more often not promoted or given tenure. Bernice Sandler's activism led to the passing of the Title IX legislation. By mandating to treat all students equally in all aspects of the education, especially in areas regarding admissions, recruitment, financial assistance, etc., in all federally funded institutions, Title IX eliminated all such practices, creating a more gender-equitable environment in education. Most importantly, it was Sandler's almost single-handed initiative that set things in motion and led to changing the educational landscape
Glassy Dielectric Response in Tb_2NiMnO_6 Double Perovskite with Similarities to a Griffiths Phase
Frequency-dependent and temperature-dependent dielectric measurements are
performed on double perovskite TbNiMnO. The real () and
imaginary () parts of dielectric permittivity show three plateaus
suggesting dielectric relaxation originating from bulk, grain boundaries and
the sample-electrode interfaces respectively. The temperature and frequency
variation of and are successfully simulated by a
circuit model. The complex plane of impedance, -, is simulated using a
series network with a resistor and a constant phase element. Through the
analysis of frequency-dependent dielectric constant using modified-Debye model,
different relaxation regimes are identified. Temperature dependence of dc
conductivity also presents a clear change in slope at, . Interestingly,
compares with the temperature at which an anomaly occurs in the phonon
modes and the Griffiths temperature for this compound. The components and
corresponding to the bulk and the parameter from modified-Debye
fit tend support to this hypothesis. Though these results cannot be interpreted
as magnetoelectric coupling, the relationship between lattice and magnetism is
marked.Comment: Accepted in Europhysics Letter
Signature of pseudo-diffusive transport in mesoscopic topological insulators
One of the unique features of Dirac Fermions is pseudo-diffusive transport by
evanescent modes at low Fermi energies when the disorder is low. At higher
Fermi energies i.e. carrier densities, the electrical transport is diffusive in
nature and the propagation occurs via plane-waves. In this study, we report the
detection of such evanescent modes in the surface states of topological
insulator through 1/f noise. While signatures of pseudo-diffusive transport
have been seen experimentally in graphene, such behavior is yet to be observed
explicitly in any other system with a Dirac dispersion. To probe this, we have
studied 1/f noise in topological insulators as a function of gate-voltage, and
temperature. Our results show a non-monotonic behavior in 1=f noise as the
Fermi energy is varied, suggesting a crossover from pseudo-diffusive to
diffusive transport regime in mesoscopic topological insulators. The
temperature dependence of noise points towards conductance fluctuations from
quantum interference as the dominant source of the noise in these samples.Comment: 5 pages, 4 figure
Ferromagnetism and the Effect of Free Charge Carriers on Electric Polarization in Y_2NiMnO_6 Double Perovskite
The double perovskite Y_2NiMnO_6 displays ferromagnetic transition at Tc = 81
K. The ferromagnetic order at low temperature is confirmed by the saturation
value of magnetization (M_s) and also, validated by the refined ordered
magnetic moment values extracted from neutron powder diffraction data at 10 K.
This way, the dominant Mn4+ and Ni2+ cationic ordering is confirmed. The
cation-ordered P 21/n nuclear structure is revealed by neutron powder
diffraction studies at 300 and 10 K. Analysis of frequency dependent dielectric
constant and equivalent circuit analysis of impedance data takes into account
the bulk contribution to total dielectric constant. This reveals an anomaly
which coincides with the ferromagnetic transition temperature (T_c).
Pyrocurrent measurements register a current flow with onset near Tc and a peak
at 57 K that shifts with temperature ramp rate. The extrinsic nature of the
observed pyrocurrent is established by employing a special protocol
measurement. It is realized that the origin is due to re-orientation of
electric dipoles created by the free charge carriers and not by spontaneous
electric polarization at variance with recently reported magnetism-driven
ferroelectricity in this materialComment: Published in Physical Review
Low temperature saturation of phase coherence length in topological insulators
Implementing topological insulators as elementary units in quantum
technologies requires a comprehensive understanding of the dephasing mechanisms
governing the surface carriers in these materials, which impose a practical
limit to the applicability of these materials in such technologies requiring
phase coherent transport. To investigate this, we have performed
magneto-resistance (MR) and conductance fluctuations\ (CF) measurements in both
exfoliated and molecular beam epitaxy grown samples. The phase breaking length
() obtained from MR shows a saturation below sample dependent
characteristic temperatures, consistent with that obtained from CF
measurements. We have systematically eliminated several factors that may lead
to such behavior of in the context of TIs, such as finite size
effect, thermalization, spin-orbit coupling length, spin-flip scattering, and
surface-bulk coupling. Our work indicates the need to identify an alternative
source of dephasing that dominates at low in topological insulators,
causing saturation in the phase breaking length and time
Magnetic Order of the Hexagonal Rare Earth Manganite Dy(0.5)Y(0.5)MnO3
Hexagonal Dy(0.5)Y(0.5)MnO3, a multiferroic rare-earth manganite with
geometrically frustrated antiferromagnetism, has been investigated with
single-crystal neutron diffraction measurements. Below 3.4 K magnetic order is
observed on both the Mn (antiferromagnetic) and Dy (ferrimagnetic) sublattices
that is identical to that of undiluted hexagonal DyMnO3 at low temperature. The
Mn moments undergo a spin reorientation transition between 3.4 K and 10 K, with
antiferromagnetic order of the Mn sublattice persisting up to 70 K; the
antiferromagnetic order in this phase is distinct from that observed in
undiluted (h)DyMnO3, yielding a qualitatively new phase diagram not seen in
other hexagonal rare-earth manganites. A magnetic field applied parallel to the
crystallographic c axis will drive a transition from the antiferromagnetic
phase into the low-temperature ferrimagnetic phase with little hysteresis.Comment: Six pages, four figures v2: Table I added, Figures 2 and 3 edited,
text edited. August 24, 201
Critical properties of the double exchange ferromagnet Nd0.4Pb0.4MnO3
Results of a study of dc-magnetization M(T, H), performed on a Nd0.6Pb0.4MnO3
single crystal in the temperature range around T_C (Curie temperature) which
embraces the critical region | epsilon | = |T -T_C |/T_C <= 0.05 are reported.
The magnetic data analyzed in the critical region using the Kouvel-Fisher
method give the values for the T_C =156.47 +/- 0.06 K and the critical
exponents, beta = 0.374 +/- 0.006 (from the temperature dependence of
magnetization), and gamma = 1.329 +/- 0.003 (from the temperature dependence of
initial susceptibility). The critical isotherm M(T_C, H) gives delta = 4.547
+/- 0.1. Thus the scaling law gamma+beta=delta beta is fulfilled. The critical
exponents obey the single scaling-equation of state M(H, epsilon) = epsilon^b
f_+/- (H/epsilon^(beta + gamma)) where, f_+ for T > T_C and f_- for T< T_C. The
exponent values are very close to those expected for the universality class of
3D Heisenberg ferromagnets with short-range interactions.Comment: 19 pages, including 6 figure
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