title: Synthesis, Structural, and Raman Investigation of Lanthanide Nitride Powders (Ln = La, Ce, Nd, Sm, Gd, Tb, Dy, Er, Lu)

authors: Kneisel, Kiersten

abstract: Lanthanide nitride (LnN) materials have garnered significant interest in recent years due to their promising potential as heterogeneous catalysts for green ammonia synthesis under low temperature and pressure reaction conditions. Here, we report on the synthesis of an extended series of lanthanide (Ln) nitride powders (Ln = lanthanum, cerium, neodymium, samarium, gadolinium, terbium, dysprosium, erbium, lutetium) and their structural and vibrational properties. Polycrystalline powders were fabricated using a ball milling mechanochemical process, and their structural properties were assessed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experimental lattice constants deduced from XRD and TEM were compared with density functional theory-based calculated lattice constants using the Perdew–Burke–Ernzerhof exchange-correlation functional. We show that the calculated lattice constants are within 1–1.5% of the experimental values for the majority of the LnN species─a notable increase in accuracy over prior computational approaches. The frequencies of Raman scattering from the LO(Γ) phonon are reported across the series and compare well with published thin-film data on a smaller selection of the series. As expected, there is a linear relationship between the LO(Γ) phonon frequency and atomic number. Finally, we demonstrate that Raman spectroscopy can be used to detect the presence of a nanoscale oxide layer on the surface of ErN powders.

text: Synthesis, Structural, and Raman Investigation of Lanthanide Nitride Powders (Ln = La, Ce, Nd, Sm, Gd, Tb, Dy, Er, Lu) Lanthanide nitride (LnN) materials have garnered significant interest in recent years due to their promising potential as heterogeneous catalysts for green ammonia synthesis under low temperature and pressure reaction conditions. Here, we report on the synthesis of an extended series of lanthanide (Ln) nitride powders (Ln = lanthanum, cerium, neodymium, samarium, gadolinium, terbium, dysprosium, erbium, lutetium) and their structural and vibrational properties. Polycrystalline powders were fabricated using a ball milling mechanochemical process, and their structural properties were assessed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experimental lattice constants deduced from XRD and TEM were compared with density functional theory-based calculated lattice constants using the Perdew–Burke–Ernzerhof exchange-correlation functional. We show that the calculated lattice constants are within 1–1.5% of the experimental values for the majority of the LnN species─a notable increase in accuracy over prior computational approaches. The frequencies of Raman scattering from the LO(Γ) phonon are reported across the series and compare well with published thin-film data on a smaller selection of the series. As expected, there is a linear relationship between the LO(Γ) phonon frequency and atomic number. Finally, we demonstrate that Raman spectroscopy can be used to detect the presence of a nanoscale oxide layer on the surface of ErN powders.

year: 2024

title: Implant conductor assembly with improved radio frequency properties

authors: Scott, Jonathan B.

abstract: In one aspect the invention provides an implant conductor lead assembly which includes an electrode lead, and at least one field target conductor. The field target conductor(s) is located adjacent to the electrode lead to mutually couple the field target conductor to the electrode lead. The electrode lead acts to concentrate electromagnetic fields in the vicinity of the implant conductor assembly towards the field target conductor or conductors.

text: Implant conductor assembly with improved radio frequency properties In one aspect the invention provides an implant conductor lead assembly which includes an electrode lead, and at least one field target conductor. The field target conductor(s) is located adjacent to the electrode lead to mutually couple the field target conductor to the electrode lead. The electrode lead acts to concentrate electromagnetic fields in the vicinity of the implant conductor assembly towards the field target conductor or conductors.

year: 2021

title: Maori identity within whanau: A review of literature.

authors: Moeke-Pickering, Taima Materangatira

subjects: Maori identity

abstract: The study of identities is an enormous and complex undertaking. Research on identity formation has revealed a clear link between family practices and identity development. In traditional Maori times, the whanau was the place where initial teaching and socialisation of things Maori took place. While there is no single exact measure of what constitutes Maori identity (Durie, 1994), that Maori identity is still being asserted today means that the shaping of Maori identity is still occurring. Rather than attempt to cover all aspects of how Maori shape their identities, I have chosen to focus on the shaping of Maori identity within whanau. Given that this paper is about both Maori identity and whanau identity it seemed logical to review and examine the literature surrounding these two notions. In this paper I also discuss the ecological threats and supports that influenced Maori and whanau identity. Then I review literature on whanau identity from traditional and contemporary works, and explore the concept of whanau identity as a management framework. The literature on whanau does not vary from what Maori authors have expressed regarding their conceptualisations of Maori identity. The tribal structures, descent and cultural practices provide integral pathways through which whanau and Maori identity can be developed and maintained. What is of significance, is that the formation of a secure whanau identity is likely to contribute toward an overall stable Maori identity. Creating an environment where a sense of secure wellbeing among members of a whanau is nurtured, leads to members constructing a whanau and Maori identity that is meaningful to them in their lives.

text: Maori identity within whanau: A review of literature. The study of identities is an enormous and complex undertaking. Research on identity formation has revealed a clear link between family practices and identity development. In traditional Maori times, the whanau was the place where initial teaching and socialisation of things Maori took place. While there is no single exact measure of what constitutes Maori identity (Durie, 1994), that Maori identity is still being asserted today means that the shaping of Maori identity is still occurring. Rather than attempt to cover all aspects of how Maori shape their identities, I have chosen to focus on the shaping of Maori identity within whanau. Given that this paper is about both Maori identity and whanau identity it seemed logical to review and examine the literature surrounding these two notions. In this paper I also discuss the ecological threats and supports that influenced Maori and whanau identity. Then I review literature on whanau identity from traditional and contemporary works, and explore the concept of whanau identity as a management framework. The literature on whanau does not vary from what Maori authors have expressed regarding their conceptualisations of Maori identity. The tribal structures, descent and cultural practices provide integral pathways through which whanau and Maori identity can be developed and maintained. What is of significance, is that the formation of a secure whanau identity is likely to contribute toward an overall stable Maori identity. Creating an environment where a sense of secure wellbeing among members of a whanau is nurtured, leads to members constructing a whanau and Maori identity that is meaningful to them in their lives.

year: 1996-01-01