I know its related to Volt-meter accuracy & B, but I don't know what is this relation.
The main source of limitations in Hall measurements is the loading effect of your voltmeter (or electrometer in V mode) that you connect to the Hall voltage leads on your sample to measure the Hall voltage. If the sample resistivity is very high (comparable to or higher than the input impedance of your voltmeter), then the voltmeter will not be able to measure V_Hall accurately. Thus, the general requirement is that the sheet resistance of your sample has to be
Mixing of the longitudinal and Hall resistances could cause a problem. If the sheet resistance of the film is low, then it is easier. However, the Hall resistance is related to the carrier density therefore if it is high, it is difficult to measure the Hall resistance.
If you consider just ideal case (which never exists) no limitation for measurements. But in reality it quite depends on contacts processing and sample preparation. For example if sheet resistance comparable or even less that contact resistance reliability of result would be very low. At the high side it is usually limited by setup (high resistance needs high voltage to get some current) and so on. Any case have to be discussed in details.
The main source of limitations in Hall measurements is the loading effect of your voltmeter (or electrometer in V mode) that you connect to the Hall voltage leads on your sample to measure the Hall voltage. If the sample resistivity is very high (comparable to or higher than the input impedance of your voltmeter), then the voltmeter will not be able to measure V_Hall accurately. Thus, the general requirement is that the sheet resistance of your sample has to be
Another source of error (or limitation) is self-heating when one is using very large values of electric current to probe the material Hall resistance. Self-heating may lead to different values of carrier concentration and mobility. That is why it is very important to choose an optimum value of the current which should be high enough to minimize noise and low enough to prevent self heating.
One should also be very careful to check if there are any parasitic current paths such as conductive substrates or conductive buffer layers. Otherwise, one may be actually measuring the Hall characteristics of the substrate or that of the conductive layer
Hope this helps.
Hi, I encourage you to look at chapter 4 of the Semiconductor Physics by Karlheinz Seeger. there you find some relations.
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