 Phase change memory is arguably the most advanced emerging non-volatile memory technology. It is already being commercialized in non-volatile memory in conventional computing systems with much faster access times than flash memory. It is also being explored for emerging computing paradigms such as in-memory computing and brain-inspired neuromorphic computing. The key element of a phase change memory cell are certain materials that exhibit significant change in electrical properties depending on whether they are in the ordered crystalline state or in a rather disordered amorphous state. The information is now encoded in the phase configuration of the material and we can reversibly change the phase configuration by applying electrical pulses of only a few nanosecond duration. We asked ourselves the questions, what would be the simplest material we can think of? Well, that would be a pure element. Our results now published in Nature Materials show that pure antimony can indeed be switched in a device structure between the crystalline and the amorphous state and it shows similar characteristic properties like typical phase change materials. However, the amorphous state we created is not very stable against crystallization, so it means that the memory is not capable of retaining the stored information for very long but we could show that fortunately if we scale our device to ultra-small dimensions so that means we have a very thin layer of only a few tens of atoms then the phase change material gets significantly more stable against crystallization. With the demonstrated retention times the devices may already be useful for certain memory type applications such as database analysis in conventional computing systems. Also, it is ideal for in-memory computing applications like machine learning and deep learning. In the future, we hope to improve the retention times of our devices further by possibly building even smaller devices or by changing the interfaces of the material.