Studying the Chemistry-Property Relationship in Magnetic and Optical Materials: Spin S = 3/2 Systems of Neodymium, Manganese, and Cobalt Oxyanions

Author

Xudong HuaiFollow

Date of Award

8-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Committee Chair/Advisor

Prof. Thao Tran

Committee Member

Prof. Jeffrey Anker

Committee Member

Prof. Joseph Kolis

Committee Member

Prof. Ya-ping Sun

Abstract

This dissertation describes the design and tunability of new magnetic and optical materials, emphasizing the intricate relationship between their crystal structures and their optical, electronic, and magnetic properties.

Two new frustrated magnets, ANd(SO₄)₂ (A = Rb, Cs), were designed and synthesized to examine the influence of the the counter cation A site in Nd lanthanide materials featuring a distorted triangular magnetic lattice with S = 3/2. This work demonstrates how the tunability of magnetic and photoluminescent properties can be achieved through the A sites, with findings validated through density functional theory calculations.

AMnTeO₆ (A = Ca, Sr, Pb) materials also feature an S = 3/2 triangular lattice. By comparing spin-polarized band structures, chemical bonds, and physical properties of AMnTeO₆, this research demonstrates how bonding analysis provides a deeper understanding of magnetic exchange interactions. It offers insights for manipulating spin dynamics with atomic precision to stabilize incommensurate magnetic ground states and significant quantum fluctuations with relatively large spin quantum numbers.

Additionally, we designed CaCo₂TeO₆ with a new diamond magnetic lattice, that exhibits field-dependent antiferromagnetic magnetic transitions and nonlinear optical responses. Unlike the commonly known spinel structure A²⁺B²⁺₂X^2-₄, where A²⁺ ions feature tetrahedral local symmetry, the Co²⁺ ions in CaCo₂TeO₆ are situated in pseudo-octahedral symmetry. This configuration allows more effective competing exchange interactions and a higher electronic instability around the Fermi level, highlighting the role of the local structure of magnetic atoms in tailoring magnetic properties.

The dissertation also reviews guiding principles for designing NCS materials, emphasizing the differences and connections between nonlinear optical (NLO) materials and magnetic skyrmions. It demonstrates how fundamental principles can drive the creation of integrated systems with desired functionalities.

Recommended Citation

Huai, Xudong, "Studying the Chemistry-Property Relationship in Magnetic and Optical Materials: Spin S = 3/2 Systems of Neodymium, Manganese, and Cobalt Oxyanions" (2024). All Dissertations. 3701.
https://open.clemson.edu/all_dissertations/3701

Author ORCID Identifier

0000-0002-8724-1880