Transition metal nitrides, nitridometalates and carbodiimides, as well as strontium acetonitriletriides: Chemical, structural and physical characteristics Von der Fakultät Chemie der Universtität Stuttgart zur Erlangung der Würde eines DOKTORS DER NATURWISSENSCHAFTEN – Dr. rer. nat. – genehmigte Abhandlung Vorgelegt von William P. Clark Hauptberichter: Prof. Dr. Rainer Niewa Mitberichter: Prof. Dr. Hans-Joachim Massonne Prüfungsvorsitzender: Prof. Dr. Thomas Schleid Tag der mündlichen Prüfung: 07.06.2019 Institut für Anorganische Chemie der Universität Stuttgart 2019 “A straight line may be the shortest distance between two points, but it is by no means the most interesting.” -The Doctor, Doctor Who Contents Abstract ............................................................................................................................................... I Zusammenfassung ............................................................................................................................. V 1. Introduction ................................................................................................................................. 1 2. Experimental methods ................................................................................................................ 7 2.1. Chemicals used .................................................................................................................... 7 2.2. Glove box ............................................................................................................................. 8 2.3. Arc furnace .......................................................................................................................... 9 2.4. High temperature apparatus ................................................................................................. 9 2.4.1. Tube furnace ................................................................................................................ 9 2.4.2. Ammonia flow furnace .............................................................................................. 11 2.5. Crystal growth with ampoules ........................................................................................... 12 2.6. Methods of high pressure and temperature synthesis ........................................................ 14 2.6.1. Diamond anvil cell ..................................................................................................... 14 2.6.2. Voggenreiter press with a Walker-type Multi-anvil module ..................................... 16 3. Analytical techniques ................................................................................................................ 19 3.1. Structural characterisation by X-ray diffraction ................................................................ 19 3.1.1. Generation and properties of X-rays .......................................................................... 19 3.1.2. Diffraction of X-rays .................................................................................................. 21 3.1.3. Single crystal X-ray diffraction .................................................................................. 23 3.1.4. Powder X-ray diffraction ........................................................................................... 27 3.2. Magnetism and magnetic measurements ........................................................................... 29 3.2.1. Overview .................................................................................................................... 29 3.2.2. Curie-Weiss Law........................................................................................................ 30 3.3. Raman spectroscopy .......................................................................................................... 32 3.4. Mössbauer Spectroscopy ................................................................................................... 33 3.5. Elemental Analysis ............................................................................................................ 34 3.5.1. Energy dispersive X-ray analysis ............................................................................... 34 3.5.2. Wavelength dispersive X-ray spectroscopy ............................................................... 34 3.6. Thermal Analysis ............................................................................................................... 35 3.6.1. Differential Thermal Analysis ................................................................................... 35 3.6.2. Differential Scanning Calorimetry ............................................................................. 35 4. High pressure synthesis of iron containing nitrides ............................................................... 37 4.1. Overview of iron nitrides ................................................................................................... 37 4.2. Synthesis and characterisation of NiAs-type FeN ............................................................. 39 4.2.1. Introduction ................................................................................................................ 39 4.2.2. Synthesis of NiAs-type FeN ...................................................................................... 42 4.2.3. Characterisation ......................................................................................................... 43 4.2.3.1. Structure determination of NiAs-type FeN ....................................................... 43 4.2.3.2. Crystal structure ................................................................................................ 46 4.2.3.3. Mössbauer Spectroscopy ................................................................................... 48 4.2.3.4. Electronic structure calculations ....................................................................... 50 4.2.4. Summary .................................................................................................................... 52 4.3. High pressure synthesis and characterisation of ε-Fe2MnN .............................................. 53 4.3.1. Introduction ................................................................................................................ 53 4.3.2. Synthesis .................................................................................................................... 54 4.3.3. Characterisation ......................................................................................................... 55 4.3.3.1. Structure determination and crystal structure of ε-Fe2MnN .............................. 55 4.3.3.2. Energy dispersive X-ray analysis ...................................................................... 58 4.3.3.3. Magnetic susceptibility...................................................................................... 59 4.3.3.4. Differential thermal analysis and thermogravimetry ......................................... 61 4.3.3.5. Microhardness ................................................................................................... 62 4.3.4. Summary .................................................................................................................... 63 5. Transition metal nitridometalates containing infinite linear chains .................................... 65 5.1. Overview of nitridometalates............................................................................................. 65 5.2. Synthesis and characterisation of SrLi2{Li[CoN2]} .......................................................... 66 5.2.1. Introduction ................................................................................................................ 66 5.2.2. Synthesis .................................................................................................................... 67 5.2.3. Characterisation ......................................................................................................... 68 5.2.3.1. Structure Determination .................................................................................... 68 5.2.3.2. Crystal Structure ................................................................................................ 78 5.2.4. Magnetic Susceptibility.............................................................................................. 80 5.2.5. Summary .................................................................................................................... 82 5.3. Synthesis and characterisation of Sr2[(Li1−xNix)Ni2N2] ..................................................... 83 5.3.1. Introduction ................................................................................................................ 83 5.3.2. Synthesis .................................................................................................................... 84 5.3.3. Characterisation ......................................................................................................... 85 5.3.3.1. Structure determination and crystal structure of Sr2[(Li1−xNix)Ni2N2] .............. 85 5.3.3.2. Energy dispersive spectroscopy ........................................................................ 93 5.3.4. Discussion and conclusion ......................................................................................... 95 6. Synthesis and characterisation of Sr6N[CuN2][CN2]2 ...........................................................