**6.2 Bio-magnetism**

*Transition Metal Compounds - Synthesis, Properties, and Application*

desired thickness is achieved [71, 96, 97].

**6.1 Transmission of commercial power**

**6. Applications**

system [71].

organometallic compounds (Bi, Ca, Sr., and Cu) solutions are deposited on Ag foil. An extra solvent is evaporated through burning and process is repeated until the

Unique properties of HTS make them very attractive from an application point of view due to continuous enhancement in their properties (**Figure 8**). Semiconductor sciences have been consistently depriving of novel applications of superconducting materials for quite a time now. Owing to their large persistent current, ever since their discovery, SC coils have always been envisioned to be used for sturdy magnetic field production. However, a major challenge faced by Type-I (first generation) HTSs was the suppression of superconductivity by magnetic fields induced within the materials by injected current. This ceased Type-I SC's application in fields involving high current and high fields. To overcome this problem, a new class of SC materials naming Type-II (second generation) HTSs having longer magnetic penetration as compared to coherence length were fabricated. Longer penetration depths favor the presence of superconductivity even in magnetic fields presence up to a critical value (Hc2) of induced field. Another modification in HTSs was the control of power dissipation caused by Lorentz force, by properly engineered "pinning centers" that modulate the magnetic flux generated in the

Extremely low resistance values make HTSs an ideal candidate for transmitting commercial power to the cities. However, high cost and practically impossible implication of cryogenic temperatures to such lengthy cables limit their

*Schematic overview of possible applications of HTSs. Reproduced from Ref. [59].*

**68**

**Figure 8.**

Another important application of HTSs is in the medical field for diagnostic purposes. Non-penetrating procedures are required in the field of bio-medicine to retrieve internal information of living body. Magnetic Resonance Imaging (MRI) has been frequently used for this purpose where a strong magnetic field has impinged into the body which imposes precessional motion of H2 atoms present in the body. After removal of an external magnetic field, exciting H2 atoms release energy which is detected and graphically presented by computer. Use of SC's can enhance MRI performance owing to high magnetic field induced in them due to large current flow. Before superconductor technology, it almost took 5 hours to produce single-image initially when MRI was discovered (July 3, 1977) [71].
