PDF Publication Title:
Text from PDF Page: 354
Quantum Critical Matter and Phase Transitions Chapter 280 319 compounds and extract the experimental details. For up-to-date reference, we refer to the following reviews by Stewart (2001, 2006), Coleman and Schofield (2005), von L€ohneysen et al. (2007), Gegenwart et al. (2008), Pfleiderer (2009), Si and Steglich (2010), and Stockert et al. (2011). In order to create and study a QPT, the general protocol consists of reducing with pressure, magnetic field, frustration and/or dilution the mag- netic or superconducting phase to T1⁄40. Here, the a priori question arises, whether such tuning leads to a continuous QPT? The usual justification for a QCP is the appearance of NFL behavior instead of standard FL behavior. However, other types of transitions without these quantum fluctuations could occur, eg, droplets, inhomogeneties, percolation or glassy dynamics (Seo et al., 2014). So additional criteria beyond the NFL effects are needed to char- acterized the near T ! 0 behavior, eg, the use of the Gr€uuneisen ratio, see Section 2.3. In both the Cerium-based series, Ce(Co, Rh, Ir)In5 and the uranium com- pound URu2Si2, distinct NFL behavior has been observed. We will now address the question whether this NFL behavior can be ascribed to a QCP. 4.1 The Cerium Series Ce(Co, Rh, Ir)In5 Let us now focus on an intensely studied Ce-system, viz. Ce(Co, Rh, Ir)In5 where a variety of behavior and tunings have been investigated. CeCoIn5 is a heavy-fermion superconductor with TcS 1⁄4 2:3 K that is claimed to be magnet- ically mediated (Petrovic et al., 2001b). Pressure was then applied to destroy the SC at % 3.5 GPa preceded by an anomalous change in the transport prop- erties at 1.6 GPa where TcS reaches a maximum of 2.6 K (Sidorov et al., 2002). However, an anticipated antiferromagnetic phase was only speculated to exist at “negative” pressures. Fig. 14 shows the proposed temperature–pressure phase diagram for CeCoIn5 (Sidorov et al., 2002). Since pressure tuning did not find the antiferromagnetic order, this then encourages magnetic-field tuning to drive TcS ! 0, as detected by magnetore- sistance measurements. Here, phase diagrams were proposed with a QCP at the destruction of SC, yet before the onset of FL behavior (Paglione et al., 2003). A similar phase diagram was established by Bianchi et al. (2003) from field dependent specific heat and resistivity data, including crossovers from superconducting to NFL to FL behavior. The interpretation of the QCP at 5 T was related to field-tuned antiferromagnetic spin fluctuations. However, the attempt to directly detect signs of AFM failed. The remaining tuning parameter for CeCoIn5 is doping, and specifically to substitute Cd on the In sites to effectively remove electrons. In the (In1xCdx)5 experiments, the parameter x refers to the nominal rather than the actual Cd concentration. Indeed AFM order develops with Cdx for x>7.5% as detected via specific heat and resistivity (Pham et al., 2006). In addition of SC being depressed with Cd doping, there seems to exist overlapsPDF Image | HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHS
PDF Search Title:
HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHSOriginal File Name Searched:
Chemistry-Rare-Earths-49.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |