With prosperity, decay, and another spring, molecular ferroelectrics have passed a hundred years since Valasek first discovered ferroelectricity in the molecular compound Rochelle salt. Recently, the proposal of ferroelectrochemistry has injected new vigor into this century-old research field. It should be highlighted that piezoresponse force microscopy (PFM) technique, as a non-destructive imaging and manipulation method for ferroelectric domains at the nanoscale, can significantly speed up the design rate of molecular ferroelectrics as well as enhance the ferroelectric and piezoelectric performances relying on domain engineering. Herein, we provide a brief review of the contribution of the PFM technique toward assisting the design and performance optimization of molecular ferroelectrics. Relying on the relationship between ferroelectric domains and crystallography, together with other physical characteristics such as domain switching and piezoelectricity, we believe that the PFM technique can be effectively applied to assist the design of high-performance molecular ferroelectrics equipped with multifunctionality, and thereby facilitate their practical utilization in optics, electronics, magnetics, thermotics, and mechanics among others.

PFM (piezoresponse force microscopy)-aided design for molecular ferroelectrics.

https://repositorio-aberto.up.pt/bitstream/10216/126602/2/388257.pdf

Development and application of laser hologram production techniques for the teaching of physics and the public awareness of science

The domain structure is an important characteristic of ferroelectrics One of the most intensively studied ferroelectrics is triglycine sulfate (TGS) Although many methods have been developed for 

Digital holographic microscopy for domain structure investigation of triglycine sulfate monocrystals doped with Nd

GPUs with their massive Single Instruction Multiple Data (SIMD) capability have become attractive for scientific computation. The Kirchhoff-Helmholtz Transform (KHT) is a two dimensional integral commonly used in numerical reconstruction of the object from its experimentally measured diffraction pattern (called hologram). We explore the evaluation of KHT using GPU at various levels of optimisation. These optimisations are of two types: (a) algorithmic: exploiting the symmetries inherent in KHT, and (b) programmatic: optimizations that are specific to the GPU architecture like the lookup tables, scheduling of read/writes. From the numerical experiments, we report the speedup for each level of optimisation.

Implementation of Kirchhoff-Helmholtz transform on GPU for use in digital in-line holographic microscopy

Two outstanding contributions to the knowledge of ferroelectric materials were made in 1955 A new group of ferroelectric crystals was discovered at Bell Laboratories (187,188), typified by the crystal GASH--guanidine aluminum sulfate hexahydrate They are characterized by ferroelectricity, but it is at present believed that they show only negligible piezoelectricity In addition, a firm experimental foundation for the development of a theory of ferroelectricity in perovskites has now been laid by the elucidation of the ferroelectric structures of BaTi0 3 and PbTiO 3 (50,135)

Ferroelectric and piezoelectric materials

The domain structure is an important characteristic of ferroelectrics. One of the most intensively studied ferroelectrics is triglycine sulfate (TGS). The domains in TGS cannot be observed directly by usual optical methods. Many methods have been developed for the observation of the domain structure in TGS like: the etching method, the powder deposition method, the decoration method, the nematic liquid crystal method, the pyroelectric probe technique, the cleavage method, the scanning electron microscopy method, and others. Despite of all these efforts, the domain structure in TGS still cannot be visualized routinely. We suggest a new method for observation of the domains in TGS, in particular digital in-line holographic microscopy (DILHM). DILHM allows direct visualization of the domain structure, without any preliminary preparation of the samples. A big advantage of the new method is its ability to extract information about the change of the domain structure in depth from one digital hologram only.

Domain structure investigation of triglycine sulfate by digital in-line holographic microscopy

Imaging of microscopic objects is an essential art, especially in life sciences Rapid progress in electronic detection and control, digital imaging, image processing, and numerical computa‐ tion has been crucial in advancing modern microscopy At present the 3D imaging of biological samples is done by confocal microscopes Their ability to image biological events in real time is limited by the time necessary to capture stacks of images taken through a certain plane in cells or tissues from which a 3D view is calculated Digital holographic microscopy is a new imaging technology applied to optical microscopy The digital holographic microscopy is a very advanced imaging technique because it yields a 3D volume image from a single image capture

/pdf/applications-of-holographic-microscopy-in-life-sciences-3o2cbp6z5u.pdf

Iliyan Peruhov

Papers

Domain structure investigation of triglycine sulfate by digital in-line holographic microscopy

Applications of Holographic Microscopy in Life Sciences

Digital holographic microscopy for domain structure investigation of triglycine sulfate monocrystals doped with Nd