In-Situ TEM Full Temperature Range Cooling, Heating and Electrical Biasing Sample Holder

Cryogenic cooling of specimens during scanning/transmission electron microscopy (S/TEM) has enabled the characterization of various quantum interfaces and phase interactions in strongly correlated systems. Investigation of such quantum properties at the fundamental level has historically been challenging due to inadequate spatial and temporal resolution of characterization techniques as well as inadequate sample stability. Quantum materials must be studied at cryogenic temperatures because many of the relevant properties in these quantum materials only manifest at such low temperatures.<br/><br/>Cryogenic S/TEM sample holders have not only enabled the study of quantum topological insulators in two-dimensional (2D) materials but also atomic resolution observation of battery interfaces, which is traditionally difficult to achieve because they are sensitive to air and prone to electron beam damage at room temperature. However, lack of biasing capability has limited the study of electrical responses in these materials systems. With increasing demand for batteries that function at high temperatures and material phase information across a wide range of temperatures from cryogenic to high temperature, expanded versatility will be required of temperature-controlled in-situ electrical biasing systems.<br/><br/>Here, we present a novel in-situ electrical biasing S/TEM holder that simultaneously allows electrical stimulus and high-resolution imaging of a sample in-situ across the full temperature range, from cryogenic up to high temperatures. The holder is exceptionally stable, with drift speeds across the entire temperature range comparable to standard holders at room temperature. Battery processes were demonstrated in a single nanowire system using this holder at near-liquid nitrogen temperature (&lt;-170°C) up to room temperature. Electrical biasing was performed on a nanowire sample bridging the electrodes on the biasing chip. A constant current experiment at cold temperatures on the nanowire showed a voltage drop as the reaction proceeds with the growth of a dendrite layer plated on the nanowire's surface. With the new heating capability, such experiments are extended to &gt;1000°C using heating on the same chip that electrically biases the sample to achieve these higher temperatures. This enables studying the temperature dependence of chemical and microstructural evolution under electrical bias. Far below room temperature where on-chip temperature measurements become increasingly inaccurate, precise temperature control is maintained using a conventional resistance heater and miniature thermocouple at the sample in the TEM holder tip. At intermediately cold temperatures, the on-chip heating/temperature sensing can be combined with tip heating and temperature measurement for precisely controlled rapid heating experiments. For quantum nanomaterials, this enables their synthesis and processing to be studied across a range of different temperatures in the low temperature regime, and their quantum response to electrical biasing to be measured at cryogenic temperatures. Batteries may now be electrochemically cycled at elevated temperature and then returned to cryogenic temperature for imaging, without the need to change holders. The cryo-biasing TEM holder with heating will empower scientists to nimbly investigate structure-property relationships in materials, specifically electronic properties, across the full temperature range. This versatile tool will accelerate the development of the next generation of electronic, quantum, and energy storage materials devices.