Systematic hardness measurements on some rare earth garnet crystal

Abstract

Microhardness measurements were undertaken on twelve rare earth garnet crystals. In yttrium aluminium garnet and gadolinium gallium garnet, there was no measurable difference in the hardness values of pure and nominally Nd-doped crystals. The hardness values were correlated with the lattice and elastic constants. An analysis of hardness data in terms of the interatomic binding indicated a high degree of covalency.

Microhardness studies on as‐grown (111) faces of some alkaline earth nitrates

“…Recently, Sirdeshmukh et al [7] pointed out that within a group of related crystals, the lattice constant is a measure of the strength of binding i.e., as the lattice constant increases, the hardness decreases. Such a variation is not observed in these crystals.…”

“…In the recent period considerable amount of work has been reported from this laboratory on hardness studies on a number of crystals like lithium niobate [6], rare earth garnets [7], ammonium and cesium halides [8], NaClO 3 and NaBrO 3 [9], also on some rare earth HCP metals [10]. In continuation of our programme on growth and characterization of crystals, we have undertaken studies of growth and hardness on some alkaline earth nitrate crystals belonging to m3 point group.…”

A new nonlinear optical semi-organic material: cadmium thiourea acetate

“…The VHN of CTA (81) crystal is low compare with the other semi-organic crystals like ZTS crystal (1 1 6) and BTCC (1 3 6) [6]. A comparison with lattice parameters of the above materials suggests that the hardness value is inversely proportional to the lattice parameters [7]. Moreover, zinc thiourea sulfate crystal (1 2 0) and zinc thiourea sulfo-phosphate (1 3 1) have very close values of lattice parameters and hardness values.…”

An Attempt to Optimize ZnO-Like TCO Nanolayered Compound Thickness in Terms of a BPES-Related Physical Parameters Pondering

“…In fact, the oscillating behavior of the λ-dependent reflection in the visible domain traduces the fact that the reflectance reaches discrete p-indexed maximal values R (p) max for some particular p-indexed values λ p max of the wavelength [39][40][41][42].…”

“…Load-independent Moh's hardness (H M ) estimated from the scratch test is on the Moh's scale, which could be calculated out from the Microhardness Vickers (H v ) using the formula [42]:…”