Neutron diffraction structural study of the apatite-type oxide ion conductor, La8Y2Ge6O27: location of the interstitial oxide ion site

Apatite-type rare earth silicates/germanates have attracted considerable interest recently due to their high oxide ion conductivities. Despite evidence in support of a conduction mechanism involving interstitial oxide ions, the exact location of the interstitial oxide ion sites continues to attract controversy. In this paper we report a neutron diffraction structural study for the high oxygen excess compound, La8Y2Ge6O27. The structural model indicates that the oxide ions are located between the GeO4 tetrahedra, leading to significant localised distortions. These results, coupled with recent modelling studies, hence, support the conclusion that oxide ion migration proceeds via these tetrahedra

An Investigation Of Master\u27s Level Counselor Education Admissions Criteria: The Predictive Validity Of Undergraduate Achievement And Aptitude On The Attainment Of Counseling Competence.

The goal of this research was to examine the relationship between the Graduate Record Examination (GRE) and undergraduate grade point average (UGPA) admissions criteria and the prediction of future counseling competencies in four domain areas; knowledge, counseling skills, professional dispositions, and professional behaviors. The Counselor Preparation Comprehensive Examination (CPCE) provided the measure for knowledge, paired with the Counseling Competencies Scale (CCS), measuring counseling skills, professional dispositions, and professional behaviors. Three types of correlational analyses (Multiple-linear Regression, Pearson Product Moment, and Canonical) were used to test the relationships between the variables and subscales. Overall, significant models were produced in areas consistent with past research: GRE and UGPA scores show a relationship to CPCE scores but not the CCS skills assessment. The author concluded that counselor educators should review their admissions criteria and ensure that the value that they place on the GRE and UGPA criteria is backed by research. Recommendations for future research should focus on the use of alternate admissions criteria which assess applicants for personal characteristics and other qualities considered necessary for a counselor to be successful

The re-emergence of sodium ion batteries : testing, processing, and manufacturability

With the re-emergence of sodium ion batteries (NIBs), we discuss the reasons for the recent interests in this technology and discuss the synergies between lithium ion battery (LIB) and NIB technologies and the potential for NIB as a “drop-in” technology for LIB manufacturing. The electrochemical testing of sodium materials in sodium metal anode arrangements is reviewed. The performance, stability, and polarization of the sodium in these test cells lead to alternative testing in three-electrode and alternative anode cell configurations. NIB manufacturability is also discussed, together with the impact that the material stability has upon the electrodes and coating. Finally, full-cell NIB technologies are reviewed, and literature proof-of-concept cells give an idea of some of the key differences in the testing protocols of these batteries. For more commercially relevant formats, safety, passive voltage control through cell balancing and cell formation aspects are discussed

High-Power Recycling::Upcycling to the Next Generation of High-Power Anodes for Li-ion Battery Applications

With the growing interest in niobium-based anodes for high-power lithium-ion batteries (LIBs), current chemistries (for this application) such as Li4Ti5O12 (LTO) anodes will be superseded, and as such an efficient and effective method of recycling needs to be considered. With this motivation, a potential upcycling route is proposed for LTO for the first time, such that Li is recovered as a salt and the titanium oxide (anatase) repurposed and used in the synthesis of current generation titanium-doped niobates. Using a variety of inorganic acids: HCl, H2SO4 and H3PO4 to achieve the proton-lithium exchange, the lithium was found to be completely leached from the LTO in the former 2 acids. The latter acid was found to give incomplete leaching, with the formation of LiTiOPO4. In addition to the recovery of Li from the leached solution, we also investigated upcycling of the recovered TiO2 (anatase) into next generation anodes TiNb2O7 and Ti2Nb10O29. The rate performance of these upcycled materials was determined through the fabrication of Li half coin cells, where both materials were found to show excellent performance at high rates (219 (2) mA h g−1 and 168 (16) mA h g−1 at 2 A g−1 for TiNb2O7 and Ti2Nb10O29 respectively), highlighting the potential of this recycling strategy for LTO

Carbonate : an alternative dopant to stabilize new perovskite phases ; synthesis and structure of Ba3Yb2O5CO3 and related isostructural phases Ba3Ln2O5CO3 (Ln = Y, Dy, Ho, Er, Tm and Lu)

In this paper we report the synthesis of the new layered perovskite oxide carbonate, Ba3Yb2O5CO3. This phase is formed when 3BaCO(3):1Yb(2)O(3) mixtures are heated in air at temperatures 1000 degrees C, while above this temperature the carbonate is lost and the simple oxide phase Ba3Yb4O9 is observed. The structure of Ba3Yb2O5CO3 was determined from neutron diffraction studies and consists of a tripled perovskite with double Yb-O layers separated by carbonate layers, the first example of a material with such a structure. Further studies showed that analogous Ba(3)Ln(2)O(5)CO(3) phases could be formed for other rare earths (Ln = Y, Dy, Ho, Er, Tm and Lu). The results highlight the ability of the perovskite structure to accommodate carbonate groups, and emphasise the need to consider their potential presence particularly for perovskite systems prepared in lower temperature synthesis routes