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The identification of charge stripes in La{sub 2{minus}x{minus}y}Nd{sub y}Sr{sub x}CuO{sub 4} (Nd-214) has reenergized research on the original high transition temperature {Tc} superconductor, La{sub 2{minus}x}Ba{sub x}CuO{sub 4} (Ba-214), and related compounds. Early in the study of Ba-214, a low temperature phase transition was associated with changes in electrical properties. An apparent suppression of {Tc} near Ba x=0.125, was initially associated with a first order low temperature phase transformation. However, it was later shown that only very near Ba x=0.125 was {Tc} reduced markedly, and that the relationship between crystal structure and {Tc} is more complicated. This review well describe the low temperature crystal structures and microstructures, as well as the superconducting properties as determined from low field (1-100G) dc magnetometer measurements for Ba-214, Nd-214, and La{sub 2{minus}x}Sr{sub x}CuO{sub 4} (Sr-214). The authors will also describe some work in the related La{sub 2{minus}x}Ca{sub x}CuO{sub 4} (Ca-214). A basic knowledge of the interactions among superconductivity and low temperature phases will allow one to better understand the significance of the underlying charge stripe phases.

This is the first issue of the third volume (Spring 2000) of a technical bulletin produced for the Department of Energy's (DOE's) Federal Energy Management Program (FEMP). It is intended for Federal solar energy champions; that is, energy officers, contracting officials, facility managers, and others who plan or work on projects in which solar and other renewable energy technologies are installed in Federal government facilities, per the directives of Executive Order 13123 and the President's Million Solar Roofs Initiative. This issue contains an article about a new initiative led by DOE and the Department of the Interior/National Park Service; it involves obtaining more renewable energy systems for the national parks. Another article describes projects adding solar and wind systems to government facilities serving Native Americans, and there are other news items as well.