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Electronic aggression victimization: The relationship to academic performance and perceived social support within an online learning environment

Posted on:2013-08-22Degree:Ph.DType:Dissertation
University:Capella UniversityCandidate:Walker, Corrine EFull Text:PDF
GTID:1455390008988334Subject:Psychology
Abstract/Summary:
Several compounds in the metal-tetracyanoethylene (TCNE) family of moleculebased magnets have been studied. The first two are compounds that exhibit similar magnetic behavior as well as share an almost identical synthetic route, namely, MnII(TCNE)3/2(I3)1/2 and Mn II(TCNE)I(OH2). They both have a critical temperature of 171 K and exhibit bulk ferrimagnetism. MnII(TCNE)3/2 (I3)1/2 is the first known structure of a molecule based magnet to possess micro4-[TCNE]·- in all three dimensions. MnII(TCNE)3/2(I3) 1/2 was also shown to exhibit a pressure-induced reversible enhancement of the critical temperature up to a maximum of 273 K. Suprisingly 2-D Mn II(TCNE)I(OH2) has the same critical temperature as 3-D MnII(TCNE)3/2(I3)1/2 which may be attributed to significant dipolar interactions between the layers due to the relatively short interlayer separation. The next two compounds are the isostructural MII(TCNE)[C4(CN)8] 1/2 (M = Mn, Fe). It was shown via detailed magnetic susceptibility measurements that they both possess an antiferromagnetic ground state with Tcs of 67 and 84 K, respectively. They also both exhibit a reversible ferri- or ferromagnetic pressureinduced magnetic transition. Finally, through a Mean Field (MF) theory analysis, it was shown that expressions that relate the exchange coupling to the critical temperature could be generated for several structure-types of the metal-TCNE family of materials. Using these expressions allowed for the estimation of the exchange coupling for several metal- TCNE compounds.
Keywords/Search Tags:TCNE, Compounds, Critical temperature, Exhibit
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