# 3.28 Sspd_chapter 1_part 11_solid state of matter_crystalline nature  (Page 2/5)

 S.No. Properties Diamond cube(dc) Simple Cube(sc) Body CenteredCube(bcc) Face Centered Cube(fcc) Hexa-gonalClose_pack structure NaCl 1 Vol.of unit cell a^3 a^3 a^3 a^3 (3/2) [√3(ca^2)] a^3 2 No. of atoms percell 8 1 2 4 6 4 cations4 anions 3 No.of atoms per unit vol. 8/ a^3 1/ a^3 2/ a^3 4/ a^3 4/ [√3(ca^2)] 8/a^3 4 No.of nearest neighbours 4 6 8 12 12 5 Nearest neighbourDistance(2r) a√3/4 a/2 a√3/2 a√2/2 a/2 6 Atomic radius a√3/8 a/2 a√3/4 a√2/4 a/2 7 Atomic packingFactor π√3/16=0.34 π/6= 0.52 π√3/8=0.68 π √2/6=0.74 π√2/6=0.74 0.67 8 Examples Ge, Si and Diamond Polonium Sodium,Iron,Chromium Aluminium,Copper,Lead Magnesium,Zinc,Cadmium Ionic solids such as NaCl, AgCl,LiFMgO,CaO

Water shows an anomaly in the range from 4°C to 0°C. With reduction in temperature at and below 4°C the density decreases instead of increasing. At 0°C, the Ice Temperature, it has the lightest density. This is because of the open-pack hexagonal structure of ice crystal. From 4°C to 0°C, the phase transition is occurring through out the volume of liquid and at 0°C the phase transition is complete. At this temperature the whole mass of water is fully transformed into a solid piece of ice. Therefore at 0°C we have the lightest density of Ice. It is this anomaly which helps the survival of fishes in frozen lakes. Nine-tenth of ice-berg is submerged and one-tenth of the ice-berg is visible. Therefore we say that the tip of the ice-berg is visible.

1.11.2 ALLOTROPIC FORMS OF CARBON

There are elements which exist as different crystalline allotropes such as Carbon. This most commonly found element exists as three crystalline allotropes namely Graphite, Diamond and Buckminstefullerene Crystal also known a buckeyball structure. The structure is shown in Figure 1.56 and Figure 1.57 and their properties are tabulated in Table (1.22).

1.11.2.1. DIAMOND CRYSTAL.

In Figure 1.56 we show the Diamond allotropic form of Carbon. As shown in Fig 1.56 A , Diamond is two interpenetrating FCC sub-lattices with one sub-lattice displaced with respect to the other along the diagonal of the cube by a quarter of diagonal length (a√3)/4 where ‘a’ the lattice parameter. Since Diamond unit cell is a cube, its lattice parameter is the side of a cube as shown in Figure 1.56 B. The basic unit cell of Diamond is cube of equal sides ‘a’ length. ‘a’ is the lattice constant of Diamond. Its value is 3.57 Angstrom. The basic unit cell is subdivided into 8 subcubes ABCDEFGH. ABCD comprise the upper 4 subcubes and EFGH comprise the lower 4 subcubes. In the Figure 1.56B , subcube E is hidden due to the perspective view. The subcube A, C, in the upper layer and F,H in the lower layer contain the tetrahedral structure of carbon atoms as shown in Figure 1.56D. As a result the basic UNIT CELL has 8 C atoms at the 8 corners of the cube, 6 C atoms on the six faces of the cube and 4 C atoms in the bodies of A, C , F, H subcube. The net result is that on looking at the PLAN VIEW of Diamond Unit Cell as shown in Figure 1.56C we see one C atom sharing its 4 valence electrons with 4 C atoms at its 4 corners. This kind of structure is repeated through out.

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Got questions? Join the online conversation and get instant answers!