NMR study of AgInTe$_2$ at normal and high pressure
Robin Guehne, Carsten Kattinger, Marko Bertmer, Simon Welzmiller, Oliver Oeckler, Jürgen Haase
备注:
Main manuscript 13 pages (references not counted), 5 figures, including Supplementary Information of 4 pages (references not counted), 3 figures; submitted to The Journal of Physical Chemistry C
发表信息:
The Journal of Physical Chemistry C 2022 126 (19), 8461-8466
The ternary semiconductor AgInTe$_2$ is a thermoelectric material with chalcopyrite-type structure that transforms reversibly into a rocksalt-type structure under high pressure. Nuclear magnetic resonance (NMR) is considered to provide unique insight into material properties on interatomic length scales, especially in the context of structural phase transitions. Here, $^{115}$In and $^{125}$Te NMR is used to study AgInTe$_2$ for ambient conditions and pressures up to 5 GPa. Magnetic field dependent and magic angle spinning (MAS) experiments of $^{125}$Te prove strongly enhanced internuclear couplings, as well as a distribution of isotropic chemical shifts suggesting a certain degree of cation disorder. The indirect nuclear coupling is smaller for $^{115}$In, as well as the chemical shift distribution in agreement with the crystal structure. The $^{115}$In NMR is further governed by a small quadrupolar interaction ($ν_\mathrm{Q} \approx$ 90 kHz) and shows an orders of magnitude faster nuclear relaxation in comparison to that of $^{125}$Te. At a pressure of about 3 GPa, the $^{115}$In quadrupole interaction increases sharply to about 2400 kHz, indicating a phase transition to a structure with a well defined, though non-cubic local symmetry, while the $^{115}$In shift suggests no significant changes of the electronic structure. The NMR signal is lost above about 5 GPa (at least up to about 10 GPa). However, upon releasing the pressure a signal is recovered that points to the reported metastable ambient pressure phase with a high degree of disorder.
muT2-NMR: Micro-Scale Correlation Relaxometry for in-situ High-Pressure Nuclear Magnetic Resonance
Shanghai Key Laboratory MFree, Institute for Shanghai Advanced Research in Physical Sciences(上海先进物理科学研究院);Center for High-Pressure Science and Technology Advance Research(高压科学与技术前沿研究中心);School of Earth and Space Sciences, Peking University(北京大学地球与空间科学学院)
Phase diagram of CeRuPO under pressure investigated by $^{31}$P-NMR - Comparison between CeRuPO under pressure and the Ce(Ru$_{1-x}$Fe$_{x}$)PO system -
$^{13}$C NMR Study on Zero-Gap State in the Organic Conductor $θ$-(BEDT-TTF)$_{2}$I$_{3}$ under Pressure
我们提出了我们的$^{13}$ C NMR研究的准二维有机导体$θ$ -(BEDT-TTF)$_2$ I $_{3}$在压力下,这是建议由输运测量零间隙导体的结果。我们发现NMR自旋位移与$T$成正比,自旋-晶格弛豫速率遵循幂律$T^α$($α=3 \sim 4$),其中$T$是温度。这种行为与锥状能带色散一致,并为本材料在压力下实现零能隙态提供了微观证据。
Space efficient opposed-anvil high-pressure cell and its application to optical and NMR measurements up to 9 GPa
我们开发了一种新型的对砧式高压电池,大大提高了空间效率。钳位电池和垫片采用非磁性镍铬铝合金制成。非磁性碳化钨(NMWC)用于砧座。尺寸为29 mm \times 41 mm的组装电池能够在7 mm 3的相对较大体积上产生高达9 GPa的压力。我们的细胞是特别适合于那些需要大的样本空间,以实现良好的信噪比的实验,如核磁共振(NMR)实验。采用氩气作为传压介质,以获得良好的流体静力性。通过透明碳硅石(6 H-SiC)窗口测量来自红宝石的荧光来原位校准压力。我们测量了Cu_2O的~(63)Cu核四极共振(NQR)频率、金属锡的面内Knight位移和铂的Knight位移随压力和温度的变化。这些量可以被用作可靠的压力计,以确定在NMR/NQR实验中的原位压力值高达9 GPa。
Pressure-induced lattice instabilities and phonon softening in the orthorhombically distorted ferrimagnet Ni4Nb2O9
Center for High Pressure Science and Technology Advanced Research (HPSTAR)(高压科学与技术先进研究卓越创新中心);Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin(德克萨斯大学奥斯汀分校杰克逊地球科学学院地质科学系);National Synchrotron Radiation Research Center(国家同步辐射研究中心);High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre(巴巴原子研究中心高压与同步辐射物理部);Homi Bhabha National Institute(霍米·巴巴国立研究所);Solid State Physics Division, Bhabha Atomic Research Centre(巴巴原子研究中心固体物理部);Shanghai Key Laboratory MFree, Institute for Shanghai Advanced Research in Physical Sciences(上海物理科学研究院MFree上海市重点实验室)
Transmission of radio-frequency waves and nuclear magnetic resonance in lanthanum superhydrides
Center for High Pressure Science and Technology Advanced Research (HPSTAR)(高压科学和技术先进研究中心);Helmholtz-Zentrum Dresden-Rossendorf(德累斯顿-罗斯多夫亥姆霍兹中心);Technische Universität Dresden(德累斯顿工业大学);Max Planck Institute for Chemical Physics of Solids(马克斯·普朗克固体化学物理研究所);A.V. Shubnikov Institute of Crystallography of the Kurchatov Complex of Crystallography and Photonics (KKKiF)(库尔恰托夫晶体学与光子学综合体A.V.舒比尼科夫晶体学研究所);Shanghai Advanced Research in Physical Sciences (SHARPS)(上海物理科学前沿研究院)
The New High-entropy Compound RhMnFeCoGe4 with Cubic Non-centrosymmetric B20 Structure
Vereshchagin Institute for High Pressure Physics, RAS(俄罗斯科学院维列夏金高压物理研究所);Mikheev Institute of Metal Physics, Russian Academy of Sciences(俄罗斯科学院米凯耶夫金属物理研究所)