The complex interplay between superconducting and magnetic phases remains poorly understood. Here, we report on the phase separation of doped holes into separate magnetic and superconducting regions ...in superoxygenated La(2-x)Sr(x)CuO(4+y), with various Sr contents. Irrespective of Sr-doping, excess oxygen raises the superconducting onset to 40 K with a coexisting magnetic spin-density wave that also orders near 40 K in each of our samples. The magnetic region is closely related to the anomalous, 1/8-hole-doped magnetic versions of La(2)CuO(4), whereas the superconducting region is optimally doped. The two phases are probably the only truly stable ground states in this region of the phase diagram. This simple two-component system is a candidate for electronic phase separation in cuprate superconductors, and a key to understanding seemingly conflicting experimental observations.
The general student population enrolled in today's physics classrooms is diverse. They come from a variety of different educational backgrounds. Some demonstrate a good knowledge of natural laws of ...physics with a better understanding of mathematical concepts, while others show a fair knowledge in fundamentals of physics with a minimum knowledge in mathematics. There are few who have not been exposed to physics or mathematics in their high schools (or at least they claim it to be the case). In addition, now we have “nontraditional” students: working part-time students, older students, commuting students, and, occasionally, military veterans. Regardless of the background, the majority of the students show little or no interest in physics and exhibit anxiety toward learning the subject. In order to address such a diverse and often unmotivated student population, and excite them about physics in a timely manner, we should deviate from conventional teaching techniques. Just-in-Time Teaching (JiTT) combined with wikis is an excellent way to accomplish this goal.
The advances of the digital age have made the duty and responsibility of the professor more complex and involved. The Internet has made powerful and useful tools available to us to disseminate ...knowledge in an interesting and effective manner. In this article, I discuss one such tool: Wikispaces (wikis)—a set of interactive web pages that can be accessed and updated by a group of users using any web browser.1
We have discovered an electronically driven phase separation in super-oxygenated La2-xSrxCuO4+y, with various Sr contents. The samples have been characterized by muon spin rotation and bulk ...magnetization measurements. For all Sr levels with x < 0.125, excess oxygen produces samples with a superconducting phase with TC near 40K and a separate magnetic phase, a spin density wave that also orders near 40K. The observed magnetic region is closely related to the anomalous, 1/8th hole doped, magnetic versions of La2CuO4, and the superconducting region is optimally doped. The two phases are likely to be the only stable ground states in this region of the phase diagram. This simple two-component system may represent the most direct observation of electronic phase separation in cuprate superconductors. Thus La2CuO4, doped with substitutional Sr and interstitial O introduces an interesting new material system for the field of high-temperature superconductivity.
We have discovered an electronically driven phase separation in super-oxygenated La
2−
x
Sr
x
CuO
4+
y
, with various Sr contents. The samples have been characterized by muon spin rotation and bulk ...magnetization measurements. For all Sr levels with
x<0.125, excess oxygen produces samples with a superconducting phase with
T
C near 40
K and a separate magnetic phase, a spin density wave that also orders near 40
K. The observed magnetic region is closely related to the anomalous, 1/8th hole doped, magnetic versions of La
2CuO
4, and the superconducting region is optimally doped. The two phases are likely to be the only stable ground states in this region of the phase diagram. This simple two-component system may represent the most direct observation of electronic phase separation in cuprate superconductors. Thus La
2CuO
4, doped with substitutional Sr and interstitial O introduces an interesting new material system for the field of high-temperature superconductivity.
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